So I am getting to the point where I am about ready to drop my 289 back in my 66 coupe. The engine is freshly rebuilt with performance mods (performer rpm heads, performer rpm intake, comp cams cam, etc) but it still has the factory harmonic balancer. What are yall's opinions on this? Is it something that I should just go ahead and replace or will the original be fine? Also, would a stock replacement be sufficient or should I opt for a more expensive performance balancer?

Thanks guys

 

Personally, I'd replace it. Powerforce makes a decent balancer for a good price that has both 3 and 4 bolt hole patterns on it, and can be changed between 28oz and 50oz imbalance. That's what I'm running on my 331.

 

what determines whether or not i should run a 28oz or a 50oz?

 

289/302 upto 1981 use 28 oz balance 1982+ uses the 50oz

all 351w/c motors use 28oz

 

I would swap it while you have to motor out, its just much easier. Plus its a pain in the *** when it does go bad, the vibration and things like that always seems to happen at a time when you can't replace it.