This may happen sooner than I thought Picked up the M20 yesterday - took the side cover off and it looks really clean and nice inside. My question is on the cross member Ive researched this alot - and have conflicting info Some say you need a small block cross members, some say you use the big block cross member If you use the BBB cross member do you still need to change ebrake cables?
I'm getting ready to go from a TH350 to TH400 in a 71 GS tribute. I have to change the e-brake cables because the trans X-member is moved back farther and thus it would interfere with the TH350 e-brake cables - different geometry. I don't know if you have to move the trans X-member if going from a Th400 to a Muncie. If you don't, then you probably don't need to change the e-brake cables. I am looking for a TH400 X-member if you want a TH350 one. My change out starts next week. UticaGeoff
Crossmembers are basically all the same. One size fits all. The BB version has an oval hole for a the E brake cable E brake cables are the same. The hook that connects the cable to the crossmember is a different length to compensate
Thanks Geoff Ive read the cross member moves just a little forward. Someone told me the next set of holes, and someone else mentioned 1". I cant see how that would seriously change the ebrake cables. I have a TH350 cross member locally if I need one. Nice offer though!
Thanks Jason! Any other 'gotchas' you can think of... things that Id need but wouldn't think of? Other than the basic stuff linke clutch linkage, shifter linkage etc.
Curtis: I'm just going make a slot in cross-member. I ended up getting a new set of e-brake cables in stainless from Inline Tube for my change. My Jim Weise tranny/converter should arrive tomorrow. If it turns out you need a different "hook" for your e-brake cables, and they are the same as ones from a TH350, you can have any of my old ones. UticaGeoff
The slot isn't really needed. The cable can run over the crossmember. There were a lot of discussions on the board in the past putting it in the hole or not in the hole. I don't think my car has it going in the hole. The biggest PITA is the pilot bushing. The pilots they make today are crap. Measure the bushing and the crank. You may have to get the bushing turned down at a machine shop depending on what the hole in the crank measures. It has to be a press fit, but too tight and the input shaft wont fit. Im not machinist, but I think the difference needs to be around .0005. Please double check my press fit tolerances with a real machinist. Once you get that right, the rest is smooth sailing. The only other snag is getting the trans into the bellhousing. No matter how well aligned you get the disc lined up wit the stupid little plastic tool, the trans never seems to go all the way in. Always seems to get hung up going into the pilot. When the engine and trans is out of the car, I use a pry bar against the bell and put just a little pressure on the fork. It will depress the plate just enough to loosen up the disc so the trans slips right in. Hopefully you get the gist of what Im trying to say. When its in the car, you can assemble the linkage and have someone press the pedal a little to do the same thing.
I recently did a 4 speed swap into a 72 suncoupe . The original 350 car x member would not work with a big block :laugh: and the 4 spd set up.ou: If I recall correctly the trans mount support on the 350 x member was a little bit higher than the one for the 4 spd and the trans would hit the floor. I Used the x member from the 4 speed car, which was a 350 car. I Have heard the 350 and 455 x members are slightly different, and 4spd x members are the same as big block? o No: On the subject of the pilot bearing- lots of junk out there- use a magnet to test for iron- pick a non magnetic one, it will prevent galling on the input shaft. I had to have one machined for a 68 -430- I recall the interference fit spec was 2-3 thousands over the crank ID measure. worked perfectly! :TU:
Aside from the E brake hole and the fact that the big block crossmenber is made from a slightly thicker metal, they are identical. I'm not sure why you had a problem. My guess would be the wrong trans mount.
on my 4spd transplant, The trans mount was new and identical to the original. My 350 x member may have been bent, the car it came from had been in a pretty nasty wreck.
Later year muncies (70-74 fine spline) use the turbo 400 yoke with 32 splines. Earlier muncies use the turbo 350 yoke.
Check the frame where the X member mounts as it maybe bent upward which could push the tail of the trans up. You would notice a gap between the frame and the trans mount..
I made my own e-brake hooks after I made the swap. Truthfully I lost them after moving 4 times.. I used the stock th350 cross member with no issue. one hint I will give you is the crossmember isn't symmetrical.. there is a left and a right side. the left side is shaped differently to accommodate the shifter and linkage. on an auto car it will work in either direction, not so with the 4 speed..
