Dear Welder Series…
Have a question about using drop spindles. I have the MII crossmember with coil overs for a 53 M100. Why does it change the mounting position of the crossmember. Doesn’t this essentially drop the crossmember down another 2” in the frame . Wouldn’t the crossmember be at the same height in the frame regardless if your using regular spindle or drop spindles. I was always under the understanding that drop spindles use the same geometry as stock it just raises the spindle height and lowered the ride height.
The new reference line, 2” higher than for stock spindles, is the location of the dropped spindle relative to the lower control arm pivot hole. For the crossmember, we relate the bottom of the frame to the spindle so the vehicle sits at the desired height with the wheels and tires being used. For the upper arm towers, we relate the top of the frame to spindle height (the new reference line on the towers), and, by “default”, to the lower arm hole center.
If the crossmember was already installed in the frame, the condition you describe if correct. But for our instructions, the new reference lines are required for dropped spindles.
I hope this clears it up. It’s a good question.