I'm building a custom set up with a LT-1 T56 transmission on a 1st gen small block and have trouble with the hydraulic clutch linkage.

I have read and heard that the stock clutch MC for Chevy LT1-T56 have a 3/4" bore and that the correct stroke (on the MC) is 7/8".

Because of limited space I can't use the stock master, so I bought a Wilwood 3/4" MC and made the ratio so that the MC get 7/8" stroke by full pedal travel.

When I tested this setup tonight, with the slave cylinder mounted in the transmission, it felt like the slave cylinder got way overloaded. All the brake fluid leaked out at the slaves rear end by the push rod. I barely moved the cluth pedal and then it happened.

Are the data I use correct?
IF I have too much stroke and / or too big master, will a destroyed slave be the result, or will the clutch fork just bottoms out in the transmission before I have full pedal travel?

The slave cylinder is an after marked piece, made in Mexico. It looked and "felt" very much the same as the original one, but could it be bad?

Any other suggestions to what I have done wrong?
Personally I suspect the slave cylinder because it happened so quick. I barely moved the clutch pedal when I felt something gave in. If a too long stroke was the reason, I figure the slave eventually would be destroyed somewhere right before the end of the stroke?

I do have the original GM slave, but I don't want to try it before I've know more.

 

If the aftermarket slave leaks at the piston / rod end, you should try the GM slave.

On an LT1 T56, if you have too much clutch fluid volume, the fork will grind the pressure plate. Idle the car and try this. The slave won't blow out from this.

 

Thanks!
Not too easy to get answers on this detail level.