[AROWHED]

I've got a '96 Viper T56 in my 65 GP, on a Quicktime bell, and it uses the stock Viper hydraulic slave cylinder, shimmed so the throwout bearing is about .020" away from the pressure plate diaphragm spring, which is a Spec Level 3+ unit. I also rigged a stiff pullback spring on the bearing (not seen in photo).

The current clutch master cylinder is a .750" bore unit for a 98-02 Firebird\Camaro.
The throwout bearing, unloaded as seen in the photo, moves about .450" forward with a full pedal push and subsequent full stroke of the master cylinder. I assume the bearing moves nearly that same distance with clutch in place....thats nearly impossible to measure but I have watched it thru fork opening in bellhousing and it certainly does seem to move that far. Shouldn't that be plenty of diaphragm spring compression for full clutch release? Also I have bled this thing many times.

Problem is getting trans into 1st or reverse requires clutch pedal fully pressed and there is still a bit of struggle to get into gear, esp reverse. Not grinding but not real easy either.
I'm thinking the .750" bore master simply does not have enough volume. So looking for a compact 1" bore master with remote reservoir, any ideas? I have no idea what the "effective" bore of the concentric style slave cylinder is, for design comparison.

[AROWHED]

Picked up part number CM1288 at local O'Reillys, says it .880" bore but that is misleading. I took it apart, it has a stepped bore: .880 where the pushrod cup is but where the brake fluid will actually be its .750"bore. Ugh, the search continues.

[misterp266]

On sale too!

https://www.speedwaymotors.com/AFCO-...RoCLG4QAvD_BwE

[AROWHED]

Got a different master, OReilly # CM1274, which is a true 7/8" bore. Typical application for it is a 1983-87 Ford F250. Had to fabricate a custom length pushrod from a 7" long 3/8" grade 5 bolt, and a 1/4" steel plate mounting bracket to tilt it downwards to better align with clutch pedal. The previous bracket tilted the opposite direction due to the mounting style of the 98 Firebird master. After a lot of painstaking bleeding, it is working, getting about .600" throwout bearing travel versus the .450" from before. Next is get the new engine in and really test it.