Can one of you 4200 guys tell me the diameter of the harmonic balancer? Could be a clearance issue. Thanks

GM used 2 designs. Which year engine are you working with? Guess you are asking for the OD?

The design changed sometime during 2003.

Yes, I'm interested in the OD. I have not sourced and engine yet, but I hope to find something 2005 or later. Are the dampers interchangable? Smaller would be better for me.

2004 up 8.1"

This is the smaller of the 2 sizes. The drive pulley is part of the damper and is about 1 5/8 thick.

The damper is about 1 5/8 thick, the pulley is cut into the damper as a 6 rib micro grove belt at the side closest to the engine.

Thank you very much. That's exactly the info I was looking for.