Blue 350 engine block in 70 camaro. where's it from?

I just picked up a '70 Camaro RS with a 350. Its not the stock 350. The engine block is painted blue and I can't find the numbers. I know ford engines are painted blue but its definately not a ford engine. I was wondering if anyone knew what company sold 350 crate engines that where blue, or what GM company put blue blocks in there cars.

Pontiac and Olds blocks were painted blue in the 70's.

...or someone coulda painted it themselves....

Thanks Morley

most likely someone just painted it.