Re: 454 Flywheel Balance... INT or EXT?
Only the 454 BB and 400 SB use externally balanced flywheels, flexplates and dampers.
And the F/W's and F/P's are different so you can't use them on each other.
And they should be stock balanced so they can be used on any 454 or 400 motor!
So don't let a Machinist balance them specifically to an engine rotating assembly b/c if you do, they will have to be re-balanced so they can be used on other engines..
PS., and I am just talking about the older BB's and SB's here b/c I think some of the newer ones, (502 and 305), are extenally balanced too, but then again, they aren't made like the older two-piece crank seal motors either...