1976 231 odd fire harmonic Balancer
 

I have a 76 231 buick , the damper has cracked and has to be replaced. is the crankshaft end dia, the same as a later year such as the Grand National type crank ? as i have a balancer after market for a 3.8L grand national engine , the issue I am having is that the old original damper just slid on and the new one has a .003 interference fit. that would mean i would have to press it on or hone it out , the problem is the key way . how could i line it up as the slot for the keyway ends about an inch from the end of the crank . My question is is this a press fit ? or do i hone the damper to get it to fit?