Depends on what year the engine (crankshaft) is. The '65 flywheel is a 28oz
imbalance so it too would need to be changed, that is, if it's actually a
later model engine. I would be suspicious because a 28oz flywheel on a 50 oz
crank would still vibrate like hell. As far as I know there is no "neutral
balance" flywheel/flex plate from the factory. It's either 28oz or 50oz
imbalance unless you're running a custom crank. Be sure you figure out what
you're engine is because an out of balance condition would ruin the engine
very quickly. I wouldn't drive it until everything got worked out.

Mark


"Ironradio" > wrote in message
om...
>I realize this FSB balance issues have been asked and answered here
> before but I have an additional couple questions.
>
> I recently bought a vehicle which has a '86 5.0L Mustang engine which
> vibrated when it ran. I noticed the ring on the harmonic damper was
> cocked and thinking that was the problem, I bought a new 50 oz. damper
> to replace it with. When I pulled the bad damper off, I noticed it was
> a 28 oz model - no wonder the engine vibrated!
>
> In checking with the guy who put together this engine he admitted to
> putting on a 1965 damper - a '65 flywheel too! I checked the flywheel
> he put on and its an old 160-tooth model. (slap - slap!)
>
> Now for my question - I now have a good damper on the engine now but
> as for the flywheel, should it be a neutral balance or a 50 oz.
> imbalance? The engine runs pretty vibration free now, so I'm guessing
> that I need a neutral balance 'wheel. Is that correct? Does the '65
> 160-tooth flywheel have neutral balance? Do I need to get that old
> flywheel off of there or should it be OK?
>
> Thanks!