Can you swap a Gen 6 454 flywheel and housing onto a Gen 4 454? Are there any balanciing issues?

Will a Gen6 502 also fit onto a Gen4 454?

They are not interchangeable. I just had to buy two new ones going from Mark IV to Gen 6.

Is it the bellhousings or the flywheels that won't fit?

Its your call! the bolt patterns are the same along with the bell housings..people here have done it..

just my o2

I don't think there is any issues with the bell housings,but I believe the weight on the flywheels is different.Has something to do with the gen 6 being 1 piece rear main and the gen 4 is 2 piece.

dont do it,the weight on the flywheels are different,yes,it will bolt on,but the rotating assembly will be out of balance,and will cause premature bearing wear.

Premature bearing wear? I did it and it shook the boat to bits at idle.That was when Gen V's had just come out in a Chris Craft Stinger 222.It shook the thing on the trailer that bad.I would be able to tell you the part number you need if a buddy of mine would return my book,if you read this John.Kind of like breaking a blade off a 3 blade fan.

Forumla.. the bellhousing will fit.. the fly will fit also, but as it has been mentioned.. the fly has a differnt counter weight from gen IV to gen V and VI..
Go to your chevy dealer and but a flywheel for the Gen IV.. very resonalble, compared to Merc.
I had one of the first 502 short blocks out of the factory and chased the flywheel thing, but reused my bellhousing from my 1988 Gen IV motor..

Dick

If it were mine i would have it reballanced no matter what it came from....

Any chance someone can confirm what this casting number from the flywheel I have is for?
3973457N

Thanks everyone