WHY 4SC ?
Why Buy From 4 Speed Conversions ?
We scour the earth for the parts you need.
We give honest descriptions and pictures of the parts we sell.
We do not sell worthless parts that look good but won't fit.
GM Manual Transmission Parts is our business.
GM Part #3918098 Frame Bracket for 1968-72 A Bodies
This part has been a weak link since it was first installed on these midsize muscle cars. The
weak spot is that they are bolted to the frame behind the pivot point (putting tack welds near
the bend greatly improves rigidity). Reproduced parts exasperated the problem, by eliminating
the bend that follows the frame. Until now.
Theirs Our Part #357
As you can see one supplier has perfected this part. The part on the right is the only one available
at 4 Speed Conversions.
We have found at least 5 reproductions of this part. Only one will fit like the original.
In the pictures above we have 4 reproductions and 1 N.O.S. frame bracket.
GM Part #3846881 1962-64 Full size Zbar
Repo (top) vs. N.O.S. (bottom)
We compare reproduced parts to new old stock whenever
possible. We have not found a suitable replacement at this
time, and maybe forced to make our own in the U.S.
We have bought copies from tall the major parts distributors,
and merchants. They all have the same major and
The length of the main pipe on the repo is too long
(8 1/2" vs. 8 1/8"). This makes it too tight between
the frame bracket and engine on some cars(customer
The frame side all stud wont fit into the tube. Machining
it to allow the stud to slide in, removes the retaining
The levers (arms) are off by 10 degrees, changing linkage geometry.
This makes clutch adjustment a problem, and can have consequences
like, hard pedal, broken fork retaining spring, broken throwout
Lever Length Incorrect
The rod holes are off by 5/16". This is another change to the
geometry of the linkage.