5.7 flywheel neutral or external balance?

[Skip Fix]

So my Blueprint Engines 383 uses a 400 balancer but recommends a "late 350 weighted balance flywheel". Are one piece main seal vortecs external balance? Their chart does list a 400 flywheel for a two piece main 383. Just did not know a 350 was external balanced. And what tooth count are the standard 350 truck motors?

 

[Schurkey]

Every one-piece rear main seal 350 has a weighted flywheel/flexplate. The two-piece rear main 350s had neutral-balance flywheel/flexplate.

Do not believe the myth that the two-piece rear main 350s were "internally balanced". They are not. Folks can look at the bigass counterweight hanging off the back of the crank and not grasp that it's the same as having a weighted flywheel.

There's two diameters for flywheel/flexplates, 153-tooth and 168-tooth. On trucks, 168-tooth is more common. That also means the stock starter motor would have the diagonal bolt pattern.

 

[Skip Fix]

Thanks. I knew that about early SBC and the weight not symmetrical on crank, and thought that since the one piece cranks are round that might be the case. Also about the different tooth sizes for all Chevy flywheels SBC, 348/409, BBC-just was not sure the standard on the truck motors.