LT1/T56 Flywheel balance

Is a LT1-T56 flywheel neutrally balanced, or externally balanced.

I'm building a 383 Gen I using a '86 up one piece rear main block, with a T56 tranny. I'm trying to figure out how it needs to be balanced.

If it's not neuatrally balanced. Does someone make one that is?

Thanks

The stock LT1 flywheel in not neutrally balanced. Flywheels are available from McLeod and SLP; verify with the manufacturers that they're available neutrally balanced.

OBE is right, if you look on the engine side of an LT1 flywheel you'll see a curved square steel bar welded into place. This is b/c the LT1 is externally balanced from the factory. There are neutrally balanced flywheels available, so if your engine is neutrally balanced you should just be able to bolt it on. They're kinda pricey though...

Thanks!

Anyone have a part number for a neutrally balanced flywheel?