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I've been working on sway from TH350 to TKO600 and have tranny installed but I'm having clearence issues to install crossmember. I got parts from SST and they sent me a bracket that supposed to mount to my crossmember to attached TKO 600 at the stock location. The original crossmember has a welded support bracket that was for old TH350 that is in the way and I don't think I have enough space even if I were to remove the bracket. I've cut a hold in the tunnel to allow transmission to go up into proper postion but still won't work. Not sure if I have to cut tunnel further forward but it looks like I'd be too high at that point and the driveshaft wouldn't clear back to differential.
I'm hoping someone here has run into this and can provide some help. I've attached some pics. I took them on my back with one hand to they aren't great. Very fustrated so I'd appreciate any advice.
I am thinking you might need to get the new crossmember from SST. I know they told me specifically I could not reuse my TH350 crossmember with the TKX. I know you have a different transmission but another call to SST to verify would be pretty easy.
I did call SST and they said the only thing they show for my year is the adaptor. I called American Powertrain and they had an option for a full crossmember. See pic below. I'm hoping this works becuase it was $400.
joserpaq
Show us the whole crossmember......I *believe* that the interference you mention is with the forward facing bracket? I would have attempted to modify the crossmember before coughing up 400 bucks. Doesn't look like much interference, but then again, I cut out the welded in cross-member on my 68. Do you have a welder?
I am glad you posted close-up pictures of the ends of that automatic crossmember.... I need ideas on modifying my crossmember for installing a 200-4R. One good thing about the American Powertrain crossmember is the big path for exhaust that is has---- you can now go to true dual exhaust if you wish.
Let me find a pic of the mods that I made to bolt on the richmond 6-speed. If the interference is the forward facing bracket then I may have a simple idea for you..... be back in a sec...gotta find pictures.
Last edited by carriljc; Oct 21, 2021 at 03:23 PM.
That lowering bracket that they sent you is a weld on piece. You have to cut the th350 mount off the tranny cross-m and weld on the new one. which lowers the 600 mounting point.
Not the best pics, but it's what I found somewhat quickly. Notice that there is "L-shaped" bracket (~3/8" thick) up against the crossmember. The bottom supports are where the former manual tranny support bracket as bolted on. Up above I drilled 2 holes (directly fore and aft) and there are 2 grade-8 bolts that bolt the vertical plane of the bracket onto the crossmember.
Last edited by carriljc; Oct 21, 2021 at 03:52 PM.
I cut off the old transmission mount on the cross member and tried to fit it but the top of the cross member bumps up against the rear of the transmission behind the mount point.
I circled in the picture where the cross member bumps into the transmission. Seems like the crossmember needs to have a dip in the center where the transmission is dropping it 3-4 inches to allow the TKO and it's mount to come down a bit. I cut the hell out of me tunnel thinking that I was not up high enough but from the pics I've see from other members they fit the TKO 600 in the C3 without have to complete cutiup the tunnel. Just cutting for shifter.
Not sure what else to try. The circle is where it bumps into transmission right behind where the mount is. So I can't puch up enough to secure crossmember.
joserpaq
Isn't that "hump" over to the passenger side where the exhaust passes UNDER the crossmember? Are you certain that thing is NOT bent? Flip it over and see if it lies flat?
Last edited by carriljc; Oct 21, 2021 at 08:55 PM.
This came with the TKO600 kit. I already had modded my cross member for a 700R4 which is the same length. So I didn't use the kit mount. I also modded my crossMember for pass under exhaust back in the 80's because it's a PITA to run the pipes through two little holes and then have all that heat right next to the tranny. 20 years later you could buy the pass under cross members
Thanks. Yes. That’s the same adaptor that I bought but it just doesn’t fit with my crossmember. But my stock crossmember is completely different. I’m hoping the new complete crossmember from American power train will work. Just $400 added to the build I wasn’t planning on. My Nephew who 13 just got a welder so I could have tried to do the mod but might have been too much for him. He’s already modding my stock shifter for the offset. Hopefully his welding skills are good enough. I’ve never done any welding.
joserpaq
Isn't that "hump" over to the passenger side where the exhaust passes UNDER the crossmember? Are you certain that thing is NOT bent? Flip it over and see if it lies flat?
I think your crossmember is bent up in the middle, as if someone tried to jack up the car by putting the jack in the middle of the crossmember. My car is a ‘79 but the 600 fit without all that cutting. I used the stock crossmember with a 700R4 trans bracket from an ‘82 and everything bolted up perfectly. The only modification was to reposition the parking brake pulley slightly.
I think your crossmember is bent up in the middle, as if someone tried to jack up the car by putting the jack in the middle of the crossmember. My car is a ‘79 but the 600 fit without all that cutting. I used the stock crossmember with a 700R4 trans bracket from an ‘82 and everything bolted up perfectly. The only modification was to reposition the parking brake pulley slightly.
I was wondering about this, no one could provide a straight answer … I have an 81 with the dropped drivers seat pan. The 82 crossmember seems to be the best recipe for success. I might be going TKX, but same mount location as TKO.
I tried everything to get my stock crossmember to work but couldn't see it working no matter how much banging I do so I order the unit below from Gforce.
I tried everything to get my stock crossmember to work but couldn't see it working no matter how much banging I do so I order the unit below from Gforce.
Wont work on an 81 or 82, our seat pan is lower, cannot run exhaust any way but the factory crossover method.
but I thought we suspected your crossmember was bent? The 82 crossmember has the 700r4 mount location which should be the same as the TKO/TKX.
Yes the G-Force crossmember does work for the 81 or 82 with the lowered floor pan. Here is one installed on my 81 with a 4L60E transmission. You just have to route the exhaust back over to the passenger side and then out the back. Basically like the factory routed it but this is a true dual exhaust on mine.
Yes the G-Force crossmember does work for the 81 or 82 with the lowered floor pan. Here is one installed on my 81 with a 4L60E transmission. You just have to route the exhaust back over to the passenger side and then out the back. Basically like the factory routed it but this is a true dual exhaust on mine.
i am assuming you eventually put the body back one … I am surprised … when looking at mine it did not look possible. Are you sure you have the dropped pan? I think some 81s had the normal pan, like an 80.
it’s nice to know that it may be possible … I’d prefer to use the stock 82 crossmember like the member above used …
TKO 600 not fitting on 1980 C3
I think your crossmember is bent up in the middle, as if someone tried to jack up the car by putting the jack in the middle of the crossmember. My car is a ‘79 but the 600 fit without all that cutting. I used the stock crossmember with a 700R4 trans bracket from an ‘82 and everything bolted up perfectly. The only modification was to reposition the parking brake pulley slightly.
