71 comet 302. My flywheel is 157 tooth and clutch is 10 inch. The confusion is part numbers for a new flywheel. C3AZ6375A Is the part number of new flywheel from Melvins and rockauto. This is a Pionner brand flywheel. They say the measurements are 13.44 inches outside diameter. Mine is dead on 13.25. It also says that flywheel uses a 10.5 inch clutch. Mine is dead on 10 Inches. Maybe part numbers have changed?
C3AZ is for 1963 and that is around the time, when the Ford small block V8 like yours first came out. If it is 157 tooth 28oz external balance (actually 28.2 but nobody cares) flywheels, it should be fine. That difference in diameter? Might just be your old one is worn down a bit.
I doubt .19" larger is going to make a difference. Remember as far as starter engagement, increase is only .095". In real world 10" clutches were barely adequate, some models did use 10.5". The 11" clutch setup requires a 164T flywheel & larger bell. Those were common on 351. If you decide to go with this flywheel & clutch, install flywheel then bell & starter to see if it engages OK. I've ran std shift engines many times setting on floor or on test stand with this set up.
