I called the engine maker just to make sure it used a standard 350 external balance flywheel. It is a blueprint engines 383, rated 420/450. Would be revving to 6k. That said, theres a lot of options. Stock, light weight, aluminum. The car is used mainly for back road driving, rarely commuting or dd. Occasional drag strip, high way pulls. I'm swapping in a T56 from a 94 Z28. I have never driven a car with any sort of modified clutch or flywheel. I saw circle track flywheels are around 10 pounds, some aluminum ones around 20, and stock ar 30. What would be the best given the driving i do?

 

There is no stock external balance 350.
We also don't know what year or rear main seal your 383 nee 350 has.

If yours is 86-up one-piece and balanced to use an 86-up one-piece rear main seal flywheel with included balance weight to match the internal balance 86-up engines, you would use the 94 Z28 flywheel and done.

If your engine is a 2-piece rear main seal, balanced to use an 85-down neutral balance 350 flywheel with no weight, there are a number of aftermarket flywheels to work with that balance, bolt pattern, and the 93-97 LT1 T56. Look for a thread by Jupiter5; he made a list.

If your engine is a 2-piece rear main seal, balanced to use a 400 SBC external balance flywheel w/ a weight, there are a few aftermarket flywheels to work with that. Some of them are simply the neutral balance 350 flywheel with a bolt-on weight.

 

yes, it is a one piece rear main. i thought the 350 was internal balance because of the extra flex plates i have laying around have no weights, but my 86 305 flexplate is weighted. i think they required the 400 balancer but 350 flexplate. how would it be driving with a light weight flywheel?