This is getting a little confusing... but it looks like there is a solution to make the T56 Magnum transmission and ZR1 Twin Disc clutch fit properly using the GM hydraulic throwout bearing (pn:24237569) and the GM pilot bearing (pn:12557583).
Here is a picture of the set up on the bell housing with the Muncie transmission. This set up was installed in the car and worked perfectly. This is a picture of the relationship between the end of the input shaft on the transmission and the flange on the bell housing. The dimension is 3/16”… this is what worked. At this dimension the input shaft on the transmission slipped into the pilot bearing about 3/4".
Here is a picture of the new set up with the Quicktime LS bell housing and the T56 Magnum transmission. The dimension from the end of the input shaft on the transmission to the flange on the bell housing is ~ 1”. If I use the 0.850” thick spacer from D&D performance that Mark Stielow on Mayhem then everything works… the distance from the flange on the bell to the end of the transmission input shaft goes to ~ 3/16”. The input shaft from the T56 Magnum will be the correct length to fit into the pilot bearing, and the GM hydraulic throwout bearing will have exactly the right clearance in relation to the tip of the fingers on the ZR1 twin disc clutch.
Each combination of parts always requires a little head scratching… but it looks like this solution will work.
Chris, if your clutch is about 3" thick then you can use the same parts minus the 0.850" spacer, as long as there is no difference in the position of the pilot bearing between the Gen I and Gen IV engines.
Thanks Tim & Scott
