I need some help figuring out which engine i have. The casting number on the block is 3970010 which indicates it's a 68 327 or a 69-79 350...
So how do i tell the difference between a 327 and a 350 w/o pulling the thing apart and measuring the stroke?


TIA
Jonathan

You can't. Maybe if it has the original heads and/or manifold, you might be able to tell from those casting numbers, but there is no guarantee that they are original.

Chances are the engine is a 350.

If you can get me the casting number off the heads (it's under the valve covers) I'll see if I can tell anything else about it.

I'm pretty sure that it is a 350. With the last 3 digits 010. I got two 350 blocks that have that as the last 3 digits. I got an article somewhere that tells more about the casting numbers. I'll see if I can find it.

You could always pull the oil pan off and get the casting #'s off the crank, that'll tell you what you have.

You can measure the stroke with a dial indicator through the spark plug hole.

Dan

GO TO WWW.MORTEC.COM FOR INFO AND TO CHECK CASTING #'S

I have been adding casting numbers to my site, slowly but surely.

a sure fire way to tell what you have without taking anything apart is the suffix codes.
there are some numbers and letters right behind your alternator, on a stamp pad that sticks out from the block.
i know by experience that if the stamp pad is long and thin, its a 350, a short stubby pad is a 350 or 327.

but get the numbers off of that "pad" right on the block where the heads meet the block, in the front, on the passenger side, right below/behind the alternator.

the suffix codes i have at my site are at

http://trak.to/chwk4x4

click on : chevy small block casting numbers


good luck

if you go to amazon.com you can search for chevy #'s books, they have everything. if you want a book of your own.
i plan to add everything to my site someday

:usa: :p :usa:

Thanks everyone. I measured the stroke and it turns out it is a 350 afterall. Now for the rebuild.......