formula377

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?

1BIGJIM

iTrader: (1)

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

formula377

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

FIXX

iTrader: (2)

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

just my o2

WR-1

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.

mike tkach

iTrader: (3)

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.

fastlane40

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.

Mr Gadgets

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

FIXX

iTrader: (2)

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

formula377

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

Thanks everyone