I need to replace the clutch on my 81 Vette. There are two diameter sizes and I was wondering if anyone out there knows which size the 81 uses so I can order it before I break car down?
My engine is high horsepower and does anyone have any recomendations as to a good brand and model that will survive the HP?

Hello there, and Welcome to the C3VR!

If you have the original engine/transmission setup, the flywheel diameter is 14" w/168 teeth -(clutch diameter is 11.0",11.5")

A sure fire way to tell what approx.size clutch is in the car without taking it apart....look at the starter bolts.
If the mounting bolts are straight across pattern, you have a small 12 3/4" 153 teeth flywheel = 10.4",11.0"clutch diameter.
If they are staggered or offset, you have the larger 14" flywheel.
My '81 had a original 14" flywheel w/11.0" clutch disc in it before I pulled the engine out.
The crate engine I put in, I equipped it with a new 14" flywheel 168 tooth(due to the one piece rear main seal design)w/ either a 11.0" or 11.5" CenterForce dual friction clutch. I don't remember the exact size. Either or will fit. Hope this helps!

Reguards, Sarge

Thanks for the help, great advice. What are the advantages of the Richmond T10 tranny in your Vette? Is it an easy conversion without alot of changes? I have a Hurst 4 speed shifter and will it work with the Richmond? What is the approximate cost?

Thanks again

Keith,
The reason my car now has a Richmond T10 in it, is due to my own stupidity. The stock T10 transmission "CC" ratio(2.88:1 first gear) has 300 lb.ft. torque limit. The engine is capable of 380 lb.ft.peak. So the two figures didn't mix together to well. I'll leave it at that. lol.
I went with p/n 1304000070- "S" ratio (2.43:1 first gear)rated to handle 375 lb.ft. torque. Everything is a straight bolt. Cost was a little over $1300.w/ship+handle + gear oil.
Now I have to replace the 2.72 rearend w/ a 3.08 unit to make up for what I lost on the 1 st gear ratio. Good Luck! Sarge

Thanks for all the help!

Keith