ok a friend of mine has a "350" he took out of his truck that he is going to give to me, now the problem is that i looked up the casting numbers off of the diver side bellhousing lip, the number is 3970010 i looked it up just to find out that this block was used for the 302 of 69, the 327 of 69, and the 350s of 69-80. how do i tell which one it is, the 302 is most definately not it, but the guy who sold him the truck said it had a 327, but he thinks that its a 350. can i measure the stroke and find out, or is there an easier way, im gonna take it either way, but i need to know what it is. thanks in advance

 

Pull a valve cover off. Check the head casting number. It probabily has common smog 350 heads on it. Cause its most likely a 350.

 

There were millions of those that were made into 350s, compared to a few thousand each that were 302s and 327s.

You can't tell what displacement it is with head casting numbers of course, but you can tell if the heads are worth a flip. Most probably they're 882s or other 70s smog garbage.

The only difference between a 350 and a 327 is the crank and pistons. But there are so few 327 large-journal cranks in existence, it's most likely a 350. See the numbers above. I'd say the odds are 99% or above that it's a 350.