Hey guys this might sound kind of funny but, are OE engines internally or externally balanced?

What effects occur when the wrong dampner's are used?

 

All SBCs are internally balanced, except for the 400 which was externally balanced and uses a unique damper.

Someone is going to come along and say that the 1 piece RMS engines are externally balanced, followed by someone else who will say that they're not. Either way it makes no difference to the damper.

 

I helped a friend swap an old 327 out of a stub nose chevy van (late 60's) vin 010 into a truck that had a different balance scheme (74 or so chevy truck 350..). Memory is failing me at this point but IIRC the 327 was internal and the truck was external. Not sure on this exactly. This swap was done many many years ago.

The thing almost vibrated itself to death (fact from personal experience) . As the story goes, the freind changed the flex plate and that curred the problem. I didn't help with that part so I can't confirm the fix.

 

The 327 and 350 are both internally balanced. If the truck had a 400 and you tried to reuse the flywheel you'd have that problem.