Zf 6-speed into 72 4-speed
 

I've seen threads on installing a T-56 into the C-3's but have not been able to find one for installing a ZF 6-speed out of a C4 Corvette into a C3 Corvette. Has this ever been done before, to anyones knowledge? If a T-56 will shoe horn into a C3, and the T-56 and the ZF are similar in size, and the ZF was the manual trans from 89 to 96, I would think someone did this conversion in the past. Parts is not an issue, I have 3 transmissions and 2 bellhousings to driveshafts for the conversion.
Thanks.

The only person that I've ever seen do this is TwinTurbo, who doesn't come to CF very often any more. As I recall the bell housing is different, which required modification, you needed a hydraulic clutch ( no big deal) but probably the biggest issue was that the shift lever was noticeably further back. Iirc, he moved the motor forward to mitigate this.

I also think that you'd have to significantly modify the tunnel on a C3. The ZF is a bit of a monster.

The biggest issue with the ZF is the lack of aftermarket parts. It needs the Duel Mass stock style Clutch or the trans will rattle in newtral. But if You have all this stuff go for it. It will use a reverse pull Clutch stock but you may be able to use another Hyd pilot bearing if You wish. The stock ZF Bell housing will bolt right up. If You jump over to the C4 section there is probably a lot of info. Also go to ZF Doc.com for all kinds of info. Carolina Clutch is where to get a replacement, consider stage two as stock. My 96 GS with a B&M Ripper Shifter is the best shifting Trans I have ever driven.

I put a clutch/flywheel in my brother's '93. We had to replace the flywheel because it was smoked. We had to go with a single mass because the GM dual mass is long discontinued. Even if you find one if would be a ton of money. (I think Rock auto had one for $1200) anyways, the rattling noise in neutral was so terrible that my brother got rid of the car. It's sounds like a lower end knock with your foot on the clutch in neutral.