When we ran a full service chassis fab/turn-key hot rod shop a number of years ago, it was always useful to have threaded things around to weld into the frame for some kind of mount, etc.
Here’s a list of all our threaded things for your reference:
Master Cylinder Bracket Pedal Pivot Plate
Product Details
Brand: Welder Series
Thickness: 3/16"
4-1/4" overall length, hole is 3/8".
Designed to be used with #13704 or #20281 master cylinder mount brackets.