I have included a couple pics so you can see what we have. The crossmember installed will be removed to install your unit. A gentleman started it with his own design and gave up so I appreciate your help on this. The white line is our wheel base of 113″ and that is your Z correct? I will get what you need from that.
Thank you so much.
Dear Jeff…Jeff, the stock wheelbase dimension will usually give the “Z” location. Sometimes the look is better when the wheel/tire is ahead or back slightly from the stock location. This is because of the vehicle rake or even the stock “look” of the wheel and tire in the fender opening that changes with the new ride height. If you have the luxury of putting a fender in place and mocking the tire, it could give some relief to know the line you have was right all along. Or …
Thanks for the pictures.
I’ll try to get cut line info back to you quickly so you can get on with the build.
Dear Welder Series…
We removed the engine and the other cross member to get more accurate measurements for your work sheets. I sent a pic of front frame also. Let me know if you need anything else and thank you for all your help.
Dear Jeff…Jeff, this series of Plymouths gave us issues back in the 80’s when we had the first one to do. I think we were involved with another builder since then. He made new frame rails from the firewall forward.
The high frame arch makes it very difficult to install an independent front end.
The frame width is where the upper a-arm cross shafts will be and the frame arch is also there.
The work-around is to add to the bottom of the frame and remove from the top.
I can do some basic drawings that will show the height of the new bottom and top of the frame using the dropped spindles that you have I can do similar drawings for stock MII spindles.
Would you also please confirm the dimensions from ground to top of frame at CR and TR?
I’ll watch for your reply.
Dear Welder Series…
Let me know when your free for a call again please. The plan is to install 2×4 at 13 1/8″ high and the same width as the inside of the existing rails and it should be more than 14 in in length of clean flat surface to work with on the top. I just want to talk before I cut it up.
My drawings are all based on dropped spindles and 13” ground to the bottom of the 2×4.
Dear Welder Series…
I have attached some pics of the Plymouth for you to have a look at. I got at it this week and it really went well and I thank you so much for all your help and engineering. I left the inner upper rails in as fillers for when the fenders are installed. We have some more finish work to do but we are really happy with the results.
I have a 1977 F100 that I’m currently trying to fit a 7.3 Godzilla into. The oil pan of the Godzilla along with the twin I-beam suspension are creating some challenges.
The primary issue is the drag link at the rear of the crossmember. To fix this I’m considering putting in an ifs kit, however I’m weird – I don’t want to lower the truck and I’m perfectly happy to keep the 5-5.5” lug spacing for the wheels. I know, I know that is weird but I like the stance and wheels I have now. I’ve got some sentimental attachments to this truck as I bought when I was 14 years old – 30 years ago! The problem is all of the ifs kits that I have run across all claim 3-5” drop.
I’m looking at the wealth of knowledge on your website and from my thinking it would be completely doable to have the upper a-arm outside the frame rail and still have a close to stock track width of ~65.75” hub to hub. This would allow the frame to ‘rise up’ relative to the suspension geometry allowing for stock ride height.
My frame rails are 33.5” measured outside to outside. From what I have found so far, this would require a different steering rack that is longer than originally offered (or is normally ran on a Mustang II style suspension).
Is this in fact possible or am I missing some key detail? Any guidance to crossmembers/ a-arm kits from you guys that I could do this myself would be great!
Thanks in advance for you help!
It was great talking to you the other day; it was super helpful to get me going.
For my specific situation, I’ve drawn up a 4” square crossmember that the lower control arm and steering rack will mount to. The positions will push the control arms out such that the upper control arm will be outside my frame rail allowing the frame to rise above the standard position of most Mustang II IFS that provide 3”-5” drop (which I don’t want). Using dimensions of control arms and an MII spindle it will still be within the current hub-to-hub dimensions I have today.
Based on the outside-the-frame-rail upper control arm, first and foremost, I want to first make sure my assumptions/math is correct – the horizontal separation between the upper and lower control arm pivots (passing a vertical line through each point) should be 3.625”. ((29.5 – 22.25)/2).
Of course, I also have some other questions…
Does the center of the crossmember coincide with the center of the spindle (i.e. wheel center)? I realize this is based on the assumption that the crossmember in a Mustang II is 4” as I’m planning to use(?). Reason I ask is it seems all the Mustang II IFS kits position the crossmember centered on the original wheel centerline. I know the lower control arm mounts directly to the front of the crossmember with the rear needing a tubular support and gusset – pushing it rearward so I assume the lower control arm geometry in effect makes the spindle centered with the crossmember but wanted to confirm.
What is the angle of the spring hat viewed from the front? Also it’s relationship fore to aft with the crossmember?
The steering rack tab mounts – what would be their relative position to each other and should it be centered on my crossmember, or biased?
Paul, I know I’ve asked a lot of questions. If you prefer a phone call to talk through this versus email I’m absolutely fine with that in fact, almost prefer it.
Dear Ken… Ken, you are basically on the right track.
Please send dimensions for the attached drawings.
‘Z’ is spindle location, front-to-rear.
In MII C1, I need inside and outside measurements at each point.
In MII C2, the frame must be blocked at the finished ride height and rake you want. At each point, dimensions should be from the ground to the bottom and to the top of the frame rail.
Dimensions to the nearest 1/16” is great; to the nearest 1/8” will be ok.
I’ll get back to you with a drawing showing, I hope, how our 60-1/2” crossmember can be used to give you what you want. Or I’ll have notes explaining how the frame has to be modified.
Frame is nearly completely flat in the range of these measurements. With the lower crossmember and twin I-beam brackets in the way made getting very precise measurements difficult. It is at the correct ride height front and rear though.
At all points, the dimension to the lower frame rail was 16.75” while the dimension from the floor to the upper measured 22.625”
Look forward to your suggestions about how to make this work.
Best Regards, Ken
Thanks for the dimensions. I’ve put them in my CAD template for a 60-1/2” track width kit.
I have based my thoughts on a stock ’77 F100 tire size of 225/75/R15 which is about 28-1/4” diameter.
Using your ground to bottom of frame ride height dimension of 16-3/4”, the bottom of the frame would be 3-1/8” higher than the spindle. We allow for about 1/2” of tire “squat.
With a 60-1/2” kit, the nominal upper arm center-to-center would be 33-1/2”. The frame will not give the arms the clearance needed. The arms would be part way down the outside of the rails, too.
When we have this condition, a solution is to add to the bottom of the frame and cut away the stock frame above it (except for support ahead and behind). A section of 2x4x1/8” wall tubing, about 18” long would work. The tube would center on ‘Z. The stock frame would be cut away 6” ahead and behind ‘Z’. With a little planning, the front and rear of the 2×4 can be angled to blend into the stock frame and not look “scabbed” on.
That done, the upper arms would have clearance.
The bottom of the 2×4 would need a small c-notch for rack bellows clearance.
Your F100’s stance would then be as you have now mocked it up. I could give you cut lines information that you could use on our crossmember and upper towers.
The general idea is as shown in the attached pdf. In this example the bottom of the frame is not straight so the customer has to allow for that. The shaded area is stock frame that would be removed. There should probably be more weld length between the bottom of the stock frame and the top of the added section. This is just a concept drawing.
Let me know if this is the way you would like to go or if you have questions/comments.
Thanks for the information. Your numbers are spot on with what I’ve measured and assumed. I was using ~3” below the bottom of my frame rail as the location of my spindle center.
I sketched up a concept (attached) of a tubular cross member that will basically cradle my current frame rails making room for, as you said, the upper control arm pivot because it wants to go thru the frame in order to raise the chassis up. My sketch moves to a hub to hub of 64.75” (current TIB is 65.75”). I know this will require a lengthen steering rack (or at least spacers – I don’t know if all racks have threaded joints or not though. If so, it seems like a rather easy way to lengthen to get the pivot to coincide with the upper and lower control arm pivot.).
My thought is it would be easier to make this assembly on a bench and install than to cut and modify my frame(?). Not sure if that is a correct assumption or not…
Forgive my rather crude model and hope it gets my thoughts across.
Dear Ken… Ken, it’s probably easier to do on the bench.
Dear Welder Series… Would your 62.5” kit get the upper control arm out beyond my 33.5” frame rails?
Dear Ken… The nominal cross shaft c-c would be 35-1/2”. Clearance would depend on the control arm and the adjustment that might be required.
I would like to purchase your cross member for my 1962 Studebaker Lark station wagon. Running into issues with frame measurements. The “Z” mark is running through the shock tower preventing me from getting accurate measurements. Also, the frame goes in and out, up and down around the “Z” mark. Checking to see if you have run across this before I start cutting out the cross member and shock towers. Attaching a few pics. If you need more or have any questions, please let me know. The “4” mark is 4 inches behind “Z”. “Z” mark starts at crossmember.
This is not an easy swap but a Welder Series’ Mustang II was designed to be used in applications like yours. Probably the 56-1/2” track width will be right.
Thanks for looking at Welder Series’ parts.
Dear Welder Series…
Thanks for the reply Paul,
Ordered my 2×4 tubing. I have a question though. You state that the 56 ½ kit likes outside frame dimensions of 26-30 inches. My frame rails will be about 30 ½. Is this going to cause a problem?
Dear Dan… Dan, that should be fine.
I’ve attached cut line drawings. This “assumes” 2×4 rails, parallel to each other and level. The bottom of the frame would be at the same height as a stock Mustang II spindle. The front would be 2” lower with dropped spindles but the cut lines would be the same.
Drawing 1 is not attached because it laid out the rails and that’s info you gave me.
I hope this helps you see the installation more clearly.
Dear Welder Series… Have a quick question for you. I ordered 5/8″ shorter control arms for my project. After receiving them I realized that the 5/8″ difference was not going to allow enough clearance for the Shock Wave air bags. So, planning on switching to coil over’s for now. My question is, Can I still mount the coil over plates at TF/TR and then use spacers for the Shock Wave Coil overs? ( Just incase I ever switch control arms to use Shock Wave air bags).
Kevin here, sorry I missed your call earlier. As I said previously, I’m doing a custom front end using your mustang ii crossmember kit for coil springs. I am using 2×4 channel for the main frame rail and am looking for either the cut diagram, or just the dimensions I need to trim both the cross member and the shock tower mounts. To give you an idea, I will be doing something that looks a lot like the build linked below. I am available in the morning Monday and Tuesday next week if it would be easier to discuss on the phone.
Dear Welder Series… I want to purchase a coil spring front cross member kit. It is going into a 53 International with a stock tread width of 60-1/2″. Questions …. I have Granada rotors on MII spindles … do I need the 58″ or 60″ x-member? The frame width is 28-1/4″ out to out …. which size will work best?I have seen the Swartz build, but can find no reference to which width he used.
Dear Rich… Rich, I’m checking with Grant Schwartz now. To decide the track width kit to use, position the wheels and tires that you’ll use in the fender opening and measure wheel mounting surface to surface. 28-1/4” outside dimension might require a work-around, but let’s take one step at a time. Thanks for looking at Welder Series’ parts. Paul Horton
Dear Welder Series… Here are the measurements for the frame. The outside measurement is 28-1/4″ from 6″ ahead of Z to 1″ behind Z then tapers to 28-7/8″ at 6″ behind Z.
Dear Welder Series… I will take pictures as I go and will send you a file when the frame is done…. might be a month or so at the rate this old fart works….. and have to keep the house projects going to keep the boss happy. A Jag rear is the next stage of the project. This project is replacing my daily driver as it has seen 12 years and a lot of abuse. Engine is 5 cylinder M/B turbo and is still going strong.
Hi Paul. Prior to me cutting the notches in my clip, could you have a quick look and see if it will work. I think this ok but….. Its on a 29 Essex no fender, with 2″ drop spindles. Frame width is 24″ inside and 28″ out side, Frame is 2″ wide and 2-3/4 ” high
Dear John… Good morning, John.
I’m working on your Mustang II cut lines and realized I didn’t ask some questions yesterday:
Are the frame rails parallel? (28” & 24” from 5” ahead to 5” back from centerline) If not, what are the dimensions at those points?
You said the rails are 2-3/4” high at axle centerline. What is the frame rail height 5” ahead and 5” back from c/l?
Dear Welder Series…
The frame rails are parallel. The frame rail height 5″ ahead is c/l is 2-3/4″ and 5″ back of c/l is 3-1/8″.
When fitting the cross member last night I had to grind a little more get it to fit . In my picture to you I had the depth of the cut at 2.5″, when it is now 2-3/4 ”
Thanks so much for your help !!!!
Here are the cut lines to put the bottom of your frame 10-1/2” from the ground with dropped spindles and a 26” diameter tire.
1929 Essex MII
1929 Essex MII
1929 Essex MII
Please send pictures when you get the kit installed.
Thanks for using Welder Series’ parts.
Dear Welder Series…
Please see attached pictures of the 1929 Three Window Essex Coupe 🙂
Thanks for all your help !!! Soon to be chopped and channeled.
Dear Welder Series… Does the coilover crossmember for a Mustang II go up the outside of the frame or do you have to notch it in?
Dear Don… Hi, Don.
The crossmember and the upper spring towers get notched to fit the frame dimensions. Usually, the crossmember welds to the inside and under the frame rail but this depends on the track width, frame inside and outside dimensions, and the frame height relative to spindle height.
With this info, I’ll be able to show you which kit width will fit and how the crossmember and towers will have to be notched. I can also make suggestions regarding stock or dropped spindles. Then you can position your wheels and tires and see how the truck will look.
Thanks for getting back to me. I want to help you with your project.
Dear Welder Series… Hello, I was looking at your Mustang II crossmember kit. I’d like to get one for my Datsun 521. I was wondering if you would be able to decrease the width of the crossmember sections by 3” to accommodate the more narrow track width of my truck. I guess I could section it myself but that wouldn’t look as clean. The suspension parts aren’t readily available for my truck so I’d like to use this setup. Thanks, John
Dear John… Hi, John.
We can make special width crossmembers, but…
The actual track width might not turn out to be what you hoped for. The brake kit used can move the wheel in or out from where the stock Mustang II was. You might also find that narrow control arms can be used that will reduce the track width and give more clearance in the engine room for exhaust and steering, even if you will use the stock engine.
Our website has some Mustang II dimensions at http://welderseries.com/tech/tech-sharing/ifs-make-your-own/. These dims will give a track width of 56-1/2” when stock 1974-78 Mustang II rotors and control arms are used. Narrowing the dimensions, top and bottom, will bring the wheels closer together by that amount. Shorter control arms will do the same. The brakes used might move the wheels in or out. We have info about our brake kits at:
If you use 4-bolt MII rotors, there should be no change.
My suggestion is:
Get everything you need except the crossmember kit, springs, shocks, and the steering rack. (Wheels & tires, brakes, spindles, and control arms) A custom rack will have to be ordered after the width has been determined. Springs and shocks can come after that.
Remove the stock front suspension.
Block the truck at ride height.
Mock up the wheels & tires, rotors, spindles and lower control arms.
Position the tires in the fender. The tires should be very close the vertical.
Block the lower control arms at horizontal.
Measure the lower control arm mounting hole center-to-center.
Subtract that dimension from 22-1/4”. This is the amount to remove from the crossmember.
Buy our 56-1/2” kit and remove that amount from between the rack mounts.
The rack will have to be shortened the same amount.
Before doing much more, check the cost of this to be sure you are comfortable with it.
I hope this helps with this part of the project.
Dear Welder Series… Paul,
Thank you for all the information and help. I figured that the control arms would have to be shortened as well. I saw a couple of your customers vehicles who did the same thing. Have a Happy New Year.
Dear Welder Series…
Good Day. Looking for a Mustang 2 type cross member for a 37 Dodge D5 coupe. Can’t find anything on your site. Would you have such a thing? Price and how much to ship to A0L 1A0? Thanks Gary
Hi, Gary. Your Dodge frame has a high curve over the front axle which makes it more difficult to install a Mustang II front end. It would be good to read our instruction sheets. https://shared-assets.adobe.com/link/17afad9a-b219-4191-7cfb-7ee4bfa6277c/?file=Coil%20Spring%20Mustang%20II.pdf , and eye-ball “ambush” areas. It might be necessary to add to the bottom of your frame to mount the crossmember and then trim off the top of the frame to mount the upper towers. The kit you use will depend on the track width you want and if you plan to use stock-style springs and shocks or coil-overs. Thanks for looking at Welder Series parts. Once you decide on the kit you’d like, we can dial in the freight cost.
Dear Welder Series…
Hi Paul Thanks for your informative reply. I will have a closer look at what I have and go from there. Now I said Mustang II front end, but it doesn’t have to be. Is there something else that would an easier install using the stock rails? Gary
Hi, Gary. A nice thing about the Mustang II is that new parts are readily available. Coil springs and coil overs are available with a wide range of rates so that the front end gets installed knowing that the ride height and the ride quality you want will happen when the vehicle is finished. Another advantage is that most, often all, sheet metal, bumper, and rad mounting holes can be used because the MII gets installed in the stock frame. I hope this info helps.
Dear Welder Series… Would you have a Mustang 2 crossmember solution for my problem. My frame rails curve inward and gets narrow at the crossmember/motor mount location so I would require a crossmember of about 24” wide between the car’s frame. The problem is my track width is 62”. Available Mustang 2 crossmember kits that measure 24” typically have a track width of only about 56”. Do you have any ideas on how I can retrofit a Mustang 2 crossmember kit into my ‘65 Lincoln short of having to replace the frame with straight pieces to get rid of narrow the section? Would longer upper & lower control arms and a longer top hat be a good option for providing a wider track for a narrow crossmember? Please Advise, Thanks!Gilbert
Dear Gilbert… I think you should consider adding straight sections of plate steel to make the frame wider in the crossmember/upper tower area. This would be top, bottom and outside pieces to give an outside dimension of 35 – 36”. Then trim the stock frame inside the new pieces and add the fourth side. Now the crossmember can be mounted under and inside the frame and the towers can weld on top and outside. There are some pictures in the Mustang II section of our website showing frame pieces in stock frames. It is not an easy job. The longer control arms would require a special rack and this could start a whole new set of things to adapt to. Thanks for asking us about this.Paul Horton
Dear Welder Series… Thanks for the recommendation and quick response! You confirmed what I was dreading, the frame has to be modified. I apologize if this sounds ignorant but to exhaust the other option, could longer tie rods/ends (approximately 3” longer each side) be used on the steering rack to accommodate the longer control arms? Or would this throw off other steering parameters? Appreciate the advice,Gilbert
Dear Welder Series… Hi Paul Building a 51 Merc do you have know which width will work best, also I don’t see it listed but do you have an already or mostly welded kit? Thanks
Dear Jeremy… Jeremy, if your Mercury is a pickup (M1), use our F1 Mustang II kit or our 60-1/2” custom fit kit. You can also use our kits for coil-overs. If your Mercury is a passenger car, it will be necessary to modify the front frame section to install the Mustang II crossmember. Check the thumbnail pics on our website and read our instruction sheets while you look at your car’s frame.
Dear Welder Series… I’m building a 1957 F100, and would like to use some of your products, but I have a few questions.
I want to use your mustang 2 crossmember with coil overs, but I’m wanting to set the ride height of the truck pretty low, so clearance for wheels in turning becomes a concern. Would I be better off using your middle width m2 crossmember, and modify my frame, to pull the wheels in a bit? I also don’t have the wheels I’m planning to use, as I’m not quite sure what to order on backspacing. Any suggestions for that?
Dear Shane… Hi, Shane. Thanks for asking but I’m not sure that I’ll be much help. Back when we built customer projects, we used 60-1/2” kits and 7” wide wheels. There was always lots of clearance.
Because you don’t have the wheels/tires, I’d suggest working on other areas of the project until you have had time to check out more vehicles at events to see what’s been used and how that was managed.
Thanks for looking at Welder Series parts. Paul Horton
Dear Welder Series… I have a 1949 international kb1. I would like to use coil springs and the mustang 2. I think it would take the 60 inch track. Is this correct? What would be the total cost shipped to Winnipeg? Do you offer welding of the basic member? Thanks
Dear Paul, Paul, There are 2 frames for KB1’s, according to my info, 28” and 30” outside width. With either of these frames, I’d widen the frame outside dimension by adding tubing so the 60” kit has more frame surface to weld to. Read through the installation sheets hereand I think you’ll see what I mean. (30” frame outside doesn’t give any surface on top of the frame for the upper tower to weld to in the 60″ kit.)
Here is a link to the web store page for the Mustang II:
There are other parts there that you might need, too, and some videos.
The 60-1/2” kit, welded, including freight and sales tax would total C$346.50. (That’s Canadian Dollars…)
Thanks for looking at Welder Series parts for your project.
Dear Welder Series… Hi! I’m building a 53 Buick Special in Memphis and was looking for some info on Mustang 2 IFS. I’d like to build my own setup but not really sure where to begin! Any info would be greatly appreciated and any parts to get me going I would definitely purchase! Thanks for your time!
Dear Mustang II In Memphis… Thanks for looking at the Welder Series site and asking about our parts for your project.
The easiest way (and it’s not easy…) is to cut off the stock frame at the firewall and use rectangular tubing as new front frame rails. The Mustang II crossmember and towers will mount to them. It will be necessary to fab mounts to support the rad (cradle) and front end sheet metal. There are several pictures on our website where builders have done this. See them at: