Must be cooking over there, it's 100 F here and the pavement I was working on yesterday was 143 F. Warmed up the toes a bit.
If you buy a stock replacement flywheel you won't have to worry about external or internal balance, unless you have a 301 which is externally balanced. Some Ford and Chev engines were externally balanced using the flywheel and harmonic damper to balance the crank. While the Pontiacs are considered internally balanced, once the whole rotating assembly was put together there was a slight [just an ounce or so] imbalance so the flywheels/flex plates were drilled. They are still considered internally balanced as the crank was balanced. Externally balanced engines have large weights attached to the flywheel. If you rebuild your engine and balance the rotating assy you will want a neutral balance flywheel. My rotating assembly is completely balanced so I use a PRW PQ series SFI neutral balance flywheel.
