Which flywheel for bbc
 

Does anyone know the gm part number for
A flywheel for a 454 1 pc rear main, 168 tooth, for
Internal balance crank.

Seems to be a lot of confusion on this subject.

Thanks to all

Don't think one was ever made for a one piece seal 454. They do have internal balanced type flywheel on a 572 crate engine. The thing in question would be if your coupler would bolt to it beings they use a 11 1/2" clutch compare to 11". #12582964 is the part number.
http://www.jrgmparts.com/GM_Performa...gm_chevy_.html

There are aluminum ones, not GM which are drilled to work with several different size clutches. Not cheap and don't if you would want an aluminum one anyway.
http://www.ebay.com/itm/McLEOD-ALUMI...-/110890974968

A stock 454 wouldn't be internal balance, not saying it couldn't have been internally balanced at a machine shop. If it truly is internal balance then the 168 tooth flywheel off of a 427 should work.

427's were Mark IV's.........2 piece seal.

one flywheel fits both one and two piecr seals and you will need to use a 427 (like mentioned) harmonic ballancer and flywheel...

I just bought one from Summit racing. like $200

After fooling with 454's for decades I would never swap flywheels with any other motor with out taking it and the balancer to a shop to be balanced.
How come your motor is internally balanced?

More info
 

I have a 454 1pc seal block. mark v
I need to buy another crankshaft and decided to go with a 4.25 stroke because I already have correct rods/pistons.
I also need flywheel and HB.

I noticed that internal bal stroker cranks are much more abundant.
I figured it would be easiest to go all neutral.

Guess I was wrong?????

I think the internal balance is better, just use the neutral balance 427 flywheel and hb. Summit, Jeg's , GM all sell them.

I just had the same deal when I stroked my GEN VI to a 489, I took my OEM factory flywheel, ground out most of the counter weights and then took it to the machine shop and for $40.00 had it nueral balanced. Done Deal. Just my 2 cents

Make sure you get a new harmonic balancer to match. Don't use your old one, it was for an externally balanced set up

The End
 

Got it
427 or machine one to neutral.

Thanks to all!!!!

Similar issue. Rebuilding a pair of GenV 540's. Appears the previous builder internally balanced the engines, but used externally balanced flywheels and harmonic balancers. Not sure how this happened, but might explain why the port engine spit a main bearing out into the timing cover after 200 hours. Anyhow, I need two neutral balanced flywheels. Will the 427 application work for me too? Thanks.

yes,396 or 427,both are internally balanced.

2 peice rear seal 350s will also work.

Even on the GenV one piece seal crank? Also is there a special pattern for the coupler? Thanks.

fixx
 

the one piece has a smaller bolt pattern
so it wont work..