AMC 360 Harmonic balancer

I am rebuilding a 360. From the cylinder heads casting I believe it is a 71 or 72 motor. The harmonic balancer rubber looks about to go, so I'm looking for a replacement. There are several listings on E-Bay all showing to fit 74 and later. The balancer doctor on line list a 70-72 and 73-81, with a note 3 bolt for the 70-72, 4 bolt for 73-81, mine is a 4 bolt, referring to the number of bolts used to attach the pulley to the balancer. My question is are they they the same except for the number of bolts attaching the pulley ?

Thanks.

 

Yes, AFAIK. I understand you can use the 4-bolt in place of the 3-bolt if you take the pulley along with it. Ie, there's no alignment difference. The balance of the two is the same.

I suggest you just replace what you have. You could try to find a good used balancer if you want ... try WTB at www.ifsja.org/forums

 

That what I suspected, I have the 4 bolt pulleys both 2 and 3 groove.