I'm sure I've read somewhere on here before, but I can' t seem to find where, do all series II harmonic balancers interchange? I've got one off of a 96+ (I think it'* a 98 ) and I've got somebody wondering if it will work on an 89

A 96 balancer won't work on an 89. Not even close.

I didn't think it would, but I really haven't had the chance to check out some of the older 3800s. Thanks.

The 96-99 and even into the 00'* may cross or work.. It is a totally different balancer than an 89 though. Be careful on your era..they were changing the balancers with nearly every year at that point and you can cause a bit of vibration with the wrong one.

It would be best to just bite the bullet and buy a new one. Even if you found one on a car the same year as the one you need, who knows how long it would last? Buy a new one and be done with it. On parts like that the peace of mind you get from knowing you don't have to deal with the same thing again for a while is worth it.

You misunderstand. I have spare ones and somebody is wanting to buy one from me. I just wanted to make sure I wasn't gonna give him something that wouldn't work. I did refer him to our site here though, figured, what the heck.

Nope, I didn't misunderstand. I simply stated my opinion on installing a used harmonic balancer. I'm cheap, in fact I am extremely cheap, but some things I just won't skimp on to save a couple of bucks. I would never even consider reusing brake pads or shoes for instance. While I have something apart, I just replace wear parts like that with good new stuff and it won't be a problem anymore. That'* just my opinion. You know what they say, everybody'* got one...