Well still trying to get this motor together. Ran into another problem.The flywheel I have will not bolt to the Bravo 1 flex plate.Can someone direct me to the proper flywheel? Here are the numbers on my block. It is a Gen V 454. Thanks Mike.

It would be better or Safer to find you a part number for a NEW flywheel if You could post your engine serial number.

Here is some info on where the serial # could be found on a MerCruiser engine.
https://appcenter.mercurymarine.com/...Locator-mc.jsp

just go to a local parts store, get a std truck flywheel for the block you are using, gen IV takes one, gen V,VI take another, thats what I've always done, never had a issue....Rob

Mike,
If the flywheel you have is the correct one for the engine, it would be a pretty easy job to redrill it for the correct bolt pattern for your coupler plate. If you do decide to go with a new flywheel, keep in mind that the GenV and newer engines are balanced differently than the MKIV's plus the flywheel for engines with cast crankshafts is balanced differently than the one for engines with steel crankshafts.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Do you have to get a MarkIV flywheel rebalanced to use it with a GenVI forged crank?

Bill. I had the engine in a 81 Hawaiian jet. At idle to about 1200 rpm it had a vibration that I thought was the jet drive coupler. But do you think it was because I have the wrong flywheel on engine? I bought it off E bay.Here is a picture of the number on back of wheel. Might be my vibration problem??? I looked up the block numbers in first picture. It is a 92 or newer 4 bolt main Gen V engine.So is this the wrong flywheel for a GEN V? Here is the number on the flywheel. I think the best bet is to buy a new one.I don't think I could drill it.

Yes,
The balance is different.

I have a Gen V, 454 mag flywheel if it will work for you.

Thanks BillK, I'll look into new flywheels

Mike,
Sorry I did not reply sooner, have been real busy I will look up that flywheel number in the morning at the shop and let you know if it is correct for your engine.