Is there a difference between a 6 3/4" and 8" balancer, besides the obvious 1 1/4"?

 

I guess you could have some clearance issues, depending on what front accessory drive you are running...

I think the big deal is how it is balanced. The smaller ones tend to be for internal balanced engines and the larger ones tend to be for external balanced (like 400 engines or engines using a 400 crank) applications, although this is not always the case.

Some of them line up better with certain timing pointers if they are the appropriate size, as well.

 

Most 350s from about 69 to about 77 had the 8" damper, and they're neutral balance.

Other than the internal/external balance thing, the most likely problem you'll have is getting the timing mark right. If you still have your stock 3rd gen timing mark, the bigger balancer won't even go on, because it will hit that.

They're all the same thickness, even the ones that came on 265s and 283s that's nothing but a pulley flange.

 

I notice in your sig you are using the 142 blower, same as me. Go with the bigger balancer for sure with the blower.

I also agree with what's posted above- the timing marks on a smaller 6-3/4" balancer can be in one of two places.... either at the common 1:30 position sticking out near the driver's side leg of the water pump or at the 12:00 position straight up behind the water pump. 8" balancers only come in one timing location variety.... the 1:30 position. The position of that line on the balancer and the location of your timing tab must match to show accurate timing when you are shooting it with your timing gun. So with the 8" unit there's less likelyhood of a mismatch between the two.

Either size will clear the stock accessories/pulleys/brackets, etc. on a 3rd gen F-body.

 

8" can be either 12:00 or 1:30 o'clock. See pic.

 

Thanks for the answers guys..

 

I just to replace my 8" balancer on my 3rd gen I'm not sure the guy that built it should of even put it on... The 6 3/4 one I pulled off an 305 87 van which my 350 motor is from 91 camaro is 1/2 thinner then the 8" one but everything timed up alright. Has anyone ever heard when a Harmonic Balancer goes bad? Your gut drops when hear it let me tell you. I was happy to see when I pulled the main pulley off it and all the bolts were oblonged. I've got pics if anyone is interested. So I got a new pulley and went to the junk yard and got a new balancer and was surprised to see it smaller and thinner.

 

Supervisor: My bad. I never ran into that before. Could you tell me what the factory application was for that?