Block Applications

[Gary C.]

Have a 3970010 block with a casting date of A 8 5. Anyone have a resource handy to help me learn what I have?

[Dick W.]

Re: Block Applications

Probably a Jan 8th of 1975 or 85 block. 010 block used in about everything that Chevrolet built for many years

[Joe L.]

Re: Block Applications

Gary and Dick------

It's probably 1975; I think that the 3970010 block was out-of-production by 1985. Not that it really matters very much, anyway, though.

Some versions of the 3970010 block were 4 bolt main and some were 2 bolt. By 1975, the 2 bolt versions were FAR more predominant than the 4 bolt. There's no way to externally ID whether the block has 2 or 4 bolts except that the suffix code on the stamp pad may infer this.

If it's a 2 bolt block, it can easily be converted to a 4 bolt. The basic blocks are exactly the same. Only the 3 center caps are different + factory drilling/tapping of the extra bolt holes.

[Clem Z.]

every 4 barrel 350 truck engine i looked at

were 4 bolt mains. if the stamp pad tell it was a truck it most likely is a 4 bolt. JMHO