From flexplate to Flywheel

[chevyfireball]

My bud has bought a 94 Corvette engine. Its a 350ci with one piece rear seal. Currently has a counterweighted flexplate on it but he wants to put a flywheel on for his manual gearbox.

Are all these engines external balancing and can he just chuck on a counterweighted flywheel without doing anything else?

[fla1976]

According to Summitt, the OEM harmonic balancer is internally balanced. So, the flywheel should be internally balanced.

http://www.summitracing.com/search/Part-Type/Harmonic-Balancers/

[kwkracing]

gm stock one piece cranks use a weight on the flywheel or flexplate, bc they machined the counterweight off when they made it one piece, Round on the end. Theres a flywheel for it, but there hard to find