968ls1

I know Dave well he is a good friend and neighbor I have helped him with his conversion. Typically if you use the stock master you will need the shim but if you use the shim and there is no clearance for the bearing to move backwards as the clutch wears it will preload the fingers and eventually start to slip prematurely. Too much clearance and the clutch will not release enough. Just using the shim with out checking the clearance is asking for trouble. On thing nice about the Spec disc is that they manufacture their hub and the splined area is a Porsche spline not a Chrylser or Ford like many conversion discs. I have worked with David closely over the years to get these right for the LS conversions and he delivers a quality product. He has a full carbon multi-disc set up in his car that is really trick-one of the benefits on owning your oun clutch business.

LS1Porch

I have the 7/8" MC as well. It works well, but is a little heavy. I think a 13/16 might be a little more suited, but nobody has been the guinea pig for it yet, and that's just my best guess.

xschop

I have a spare 13/16" Wilwood that I tried after I was using the 7/8" with the C5 BH, TOB, and F-body PP......I swapped back over to the 7/8" to be 100% sure of disengagement (reverse gear was more difficult to get into with 13/16" MC).....swapping an MC beats removing the clutch/drivetrain LOL

Plus with the larger 7/8" MC you can adjust down the throw/volume to suit.....you can only go so far up in volume with the 13/16" MC

LS1Porch

Oh, you tried the 13/16 xs? Didn't know that.

Eh, reverse is hard to get into even with the 7/8". :lol:

xschop

Ain't that the truth. It's even harder with the 13/16", can't speak for the factory 944 MC (3/4" IIRC) with the LS clutch PP....I've heard the grind stories.