I recently ordered a SBC harmonic balancer for my 65 327 Corvette crate engine. The balance that I receive was for a SBC 350. It measures 6.75" diameter, 1.125" thick. My 327 balancer is 6.75" diamaeter, 5/8" thick, with the pulley rivoted to the
balance, and a gap between the balancer and the pulley.

My questions are:

Is the 350 balancer interchanangable with my 327 ? I believe I will have to buy a new pulley that fits flush with the balancer.

Also, are there any advantages, or disadvantages to using the larger 350 balance on my 327.

Thanks for any answers that I receive.

Both balancers are ok to use as long as the front mounting face is the same distance from the block, the timing mark may be in a different position so you will have to find tdc on the motor and mark the new balancer, larger balancers are great for street engines. most of the replacement balancers are for 350's, they will work on most all sbc's(various timing mark placements) except 400's.

Thanks for your reply. That's kinda what I thought. Now I just need to get a pulley that fits fairly flush with the balancer. I would think I could get one those at a local parts house.

I have a 350 balancer on my 327 in the truck.. It is definatly a lot bigger than the 327 balancer but it did fit fine. I noticed less off idle response probably because the 350 balancer is like twice the weight and takes longer to get spinning. It will be work fine.. If you havn't installed it yet you could return it and get the correct one?? Good luck.
The advantages are little smoother running engine
Dis-advantage is a little loss in off idle response