Clutch issues on manual swap

[ferretpatrol]

We have an nv3500 we're trying to swap into a truck (94 tbi) in place of a 4l60e. We're having master cylinder and clutch disengagement issues. Essentially the pedal is super stiff to the point where the firewall is trying to flex, and we're getting a little but not much movement on the clutch disk. Not disengaging at all. Has a new concentric slave/throw out bearing, new clutch disk, new master cylinder. Tranny came out of a 98. Thanks

 

[bluex]

Did you use a pressure plate for a 98 or the 94?

The earlier trans (like would have been in a 94) with external slave use a different height on the pressure plate fingers. If you use that 95 an older pressure plate with the 96+ internal slave the clutch is always disengaged as the fingers are about 1/2" higher than a 96+ one.

I found this out the hard way also

 

[WICruiser-97]

Is the stiff pedal from the up position or only after being depressed some amount?

If stiff from the up position the slave is locked up preventing the piston from moving.