Can I used a Harmonic Balancer from an 1988 330hp on a 1991 365hp? Regarding the 365 balancer ,I took it off and put it on the lath, ran it to 400 rpm and it shook bad and was out of balance. However I have a good one off the 330. Will I be able to use the 330 balancer on the 365hp?
Thanks NOBUDGET

That balancer is probably all ok-the 454 BBC balancer is not neutral balanced (will vibrate if spun in a lathe) and is weighted to offset the imbalance of the crankshaft. You can get a neutral balanced harmonic balancer but it can only be used on an internaly balanced engine. Some race engines are internaly balanced so that if they break a part they can take one off the shelf and bolt it on and not have to have the engine rebalanced. That is why if you break a harmonic balancer or a flywheel you should get the entire engine rebalanced unless your engine was balanced by a good shop and they have the weight #s an record.