I'm going to replace the harmonic balancer on my '66 425. I'm not sure if it needs one specific to that engine or will a 455 balancer work as well? Thanks.

 

I replaced the balancer on my 455 recently with a Dorman...from what I could find it was the very cheapest you can buy. I got mine at my local mom and pop shop for about $90.00 but if you go to Rockauto.com, I believe you can get it even cheaper. As for the application, the one I got was correct for a ton of different makes, models, and years all the way up to 1995. So I am about 90% sure it would work for what you need. If you go to rockauto, or to the Dorman site, they will let you know. Or give their tech support a call, they were extremley helpful and knowledgeable and spoke English too! No offense!

 

The 455 balancer won't work. Pre-'68 engines had different balance.
Consider having your original rebuilt by DamperDoctor.com, you won't be sorry.

 

What makes you say that?

 

Visually I know they're different. The 425 is much smaller than the 455. But I don't know the effects of putting on a larger one. I have seen several different sizes on 350's from 1968-72, and I don't know the rhyme or reason behind it. John

 

Yeah I just checked Dormans, the balancer I used says it only goes back to 1968. According to 442.com, the 66 425 shouldn't be swapped with a 455 balancer, but it doesn't say it can't be used. I would probably do like Copper said and just send your old one to the Damper Doc. Play it safe.

 

Actually Nick, i don't know that. but I do know the balancers and flywheel/flexplates are different. Whether the size and weight of balance weights is different, I don't really know.

 

OK, thanks. Thought maybe there was something specific that I didn't know about.

 

Thanks for the replies. Guess I'll look into getting the old one redone.

 

Diameter, width of ring, position of timing mark differ 67-back and 68-up. The overall thickness from the crank timing gear to the pulley surface are the same, and the pulley bolt pattern in the same. So, you could use a 455 balancer if you got it rebalanced to the earlier amount of counterweight, and used the later timing pointer.