FMX swap to C6 1967 F250

[vwfreak]

Getting ready to install a replacement trans for my broken FMX. Unit is a 1972 C6, short tail from a similar truck. I know this topic has probably been covered but I didn't see anything recent. I'm hoping to find issues ahead of time that others have come across in the past. Anyone know if crossmember for rear mount needs any relocation or modification? I'll definitely need to have the driveshaft reworked to attach to the different style yoke. I also need to find a suitable shift selector lever as the one that was installed in this trans had been broken nicely and rewelded poorly.... I know there's a slip on aftermarket lever and I may try one of those. Guess I could also make one....

[basketcase0302]

vwfreak » Sun Jul 03, 2016 10:45 am

Getting ready to install a replacement trans for my broken FMX. Unit is a 1972 C6, short tail from a similar truck. I know this topic has probably been covered but I didn't see anything recent. I'm hoping to find issues ahead of time that others have come across in the past. Anyone know if crossmember for rear mount needs any relocation or modification? I'll definitely need to have the driveshaft reworked to attach to the different style yoke. I also need to find a suitable shift selector lever as the one that was installed in this trans had been broken nicely and rewelded poorly.... I know there's a slip on aftermarket lever and I may try one of those. Guess I could also make one....

Yes the FMX length is not the same as the C6 if memory serves me correct. Plan on redrilling the holes into the frame where the crossmember bolts to it. I'd also recommend using the dent era C6 crossmember if you have access to it, as it is different from the bump era that I've documented in my pictures.
I'd made custom linkages for my early Bronco and my one ton by threading to different ends, (after mocking up the length) then using a stud coupler. This works out very well as it gives you adjustment if cab bushing wear / steering column issues which can cause misalignment with the sockets of the linkage.
Love...me some C-6, (be advised a lot of C-6 bashers here though) LOL!

[vwfreak]

Thanks for the info Jeff. I don't have a dent xmember but could get one if necessary. Will the bump xmember work at all...? Just had mine powder coated with the installation of the rebuild FMX which failed and is prompting the swap.
Steering column was the 1st thing I went through on this truck back in 2012 and is still jelly tight as I've only logged 4k miles since then.
I recall a pal saying he had to redrill xmember holes about 1" rearward with is swap in his '66.
Looking at my linkage rod and the levers on both the FMX and the C6 i have they're really similar.... Wondering if I can fix that crappy weld on the C6 unit and get it straight for reuse. On appearance they look the identcal shape, angle and offset.... Clearly the C6 came from a column shifted truck.
Really getting excited for this swap and hoping the upgrades make a difference, but I'm as nervous as a long tailed cat in a room full of rocking chairs hoping I didn't mess anything up in there. My 1st C6 build....

[basketcase0302]

The C-6 is practically bulletproof-tried and true for over 50 years now.
Yes your bump crossmember will work. What i found was that the dent crossmember lowered my C-6 another 1" to lesson the driveshaft angle, (pet peeve of mine having ran 10" lifted Bronco for years).
I would try to make the old linkage work, (even though I went the easy route and installed what one member here calls a "ghetto shifter" ).
I loved my B & M MegaTruckShifter, with the cable it is so...easy to hook up and makes a neutral safety and back up light switches so incredibly easy to boot!
BobbyFord can also tell you a lot about the C-6 as he's tried and tried I believe to break his and hasn't LOL!

[vwfreak]

The C-6 is practically bulletproof-tried and true for over 50 years now.
Yes your bump crossmember will work. What i found was that the dent crossmember lowered my C-6 another 1" to lesson the driveshaft angle, (pet peeve of mine having ran 10" lifted Bronco for years).
I would try to make the old linkage work, (even though I went the easy route and installed what one member here calls a "ghetto shifter" ).
I loved my B & M MegaTruckShifter, with the cable it is so...easy to hook up and makes a neutral safety and back up light switches so incredibly easy to boot!
BobbyFord can also tell you a lot about the C-6 as he's tried and tried I believe to break his and hasn't LOL!

good info, Jeff. I have a two piece drive shaft. Will it be important to lower the output shaft of the trans in that instance? Also, I figured on welding up the existing shift selector. Should work out fine.

[vwfreak]

Project underway. Took me quite a ehile to build the new C6 having never done one before. Think it's all correct though.... Wide ratioFord racing kit. Transgo shift kit. 5 frictions in rev/hi and rev/low and 6 in Forward. Should be all dialed in.

FMX coming out now. Should have the new one in place this evening.