Late Model Chevy pickup Engines

[OrrieG]

Originally Posted by Kim57

The 350 is also an excellent engine and works well also.

And a lot of the truck 350's from 3/4 ton up are 4 bolt main blocks. Unfortunately you cannot tell from the casting numbers, I have a truck block in my Chevelle with the same casting number and 1974 date code (both came out of the 74 donor trucks) as the truck block, truck is 4 bolt, Chevelle 2 bolt. Both trucks were 1/2 tons, I suspect they may have gotten behind on engine production and just tossed in a 4 bolt to keep the line moving.