Another 403


Active member
Oct 3, 2018
Braceville Ohio
I'm not crazy about the solid hub-type harmonic balancer that came with the engine. I went over my buildings today and pulled a factory type with the rubber between the rings off one of my builder 403s. I came home and weighed them both. Solid hub type weighed 2,608 grams vs Factory rubber sandwiched type @ 3,804. I'm going with the solid balancer.

Olds 307 and 403

Active member
Oct 4, 2018
Melville, Saskatchewan
Yeah, I don't get how GM thought a tiny, solid balancer was a good idea on a flimsy block and big heavy pistons. Supposedly my 403 was from 78 Delta 88, old man owned. Pulled it down, found red Detroit head gaskets and .010" rod bearings. And this was with a proper balancer. 1200 grams is a big difference.