Question about balancing rotating assembly

rustycowll69 said

I took apart my relatively virgin 70 340 six pack engine, and although I can't remember the exact numbers, because that was over 40yrs ago, I was shocked how different each rod was. I think it was like 80 to 100 grams(if not higher) off from highest to lowest. I never noticed any bad vibration problems.

Click to expand...

Yep. Seen it myself. I’ve been told chrysler used what is called mass balancing. I’ve asked some of the smartest people in the industry to explain it, but no one could.

You can be pretty far off with the counterweights being heavy and it won’t hurt most Street/strip duty stuff. When the counterweights get light...hang on as they shake like a dog pooping peach seeds.