[snowicki]

Hey folks,
I am trying to figure out what engine I have. There is a number stamped on the block where it joins the transmission (driver side). The number is 3970010. I was told it was out of a Corvette.

[Jason]

They told you it was out of a corvette so you'd think it was something special. It could be, but that number is the most comon 350 chevy number of them all.
It could be a 302, 327 or 350 from 1969 to 1980.
Casting numbers aren't very specific, what you need to do is look at the suffix code stamped on the passenger side front of the block.
Stampings are most specific. This site and your codes will tell you exactly what it came out of.

[85406]

Although that casting was used in many engines it was usually in higher performance car engines or in trucks. Although my experience is not great, every 3970010 casting I have run across has also been a "010" block which has 1% higher tin than regular. There is also some that are "020" blocks which are 2% higher nickle and I have seen a picture of a 3970010 block that was both a "010" and a "020". So it might be out of a corvette, it might not, it most likely is 4 bolt but might not be. It is a good block.

[68NovaSS]

Just for information, I have a 3970010, that has 010 cast into the side of the block and under the timing cover is cast "010" and "020", but it's a 2 bolt block, pretty depressing, I need a 4 bolt for another blower motor project.

Anybody out there done the Milidon splayed 4 bolt conversion with any success? I understand the kit comes with a sleeve and stuff needed to do it yourself, then of course, have it line bored. I also read the splayed conversion is actually better than a factory 4 bolt in that the outer bolts don't use the inherently week web areas cast into those blocks.