The Stovebolt Site Forums The Shop Area The HiPo Shop tryin' to figure out what engine I've been blessed with

Went to MorTec with the casting numbers from my block.
Looked up: 3970010

and this came up:

3970010....302.....69....4...Z-28 Camaro
3970010....327.....69....2...Trucks and industrial
3970010....350...69-80...2 or 4

(1)what do the numbers for "main cap bolts" mean? :confused:


(2) Any way to narrow this down?

All I really want to do is figure out what kind of engine I have.(you know parts and other good stuff)


Please remember I am really new at this.
Thanks to all in advance!

Caps are what hold the crank in. Some were 2 bolt, some were four. The four being the stronger version. Too narrow it down, do the same with the head numbers at Mortec. The combination of both numbers will narrow down the application. If you don't have the heads, don't worry. Your block is part of the Chevy small block series. Almost any part for a small block will fit.

If you want to get technical, you could measure the bore. There were only so many bore / stroke combinations. So you could really narrow down the size of your engine.

If the block is a 350 then it should have 5.7L cast into the block just behind the drivers side cylinder head.

Those three motors all have some things in common. They use the same size journal crank and the same bore.

If there is a number stamped in the block in front of the passenger side head it might clarifiy the original application.

Casting numbers from the head might help.

Measuring the stroke would be conclusive. A 302 has a 3 inch stroke, a 327 has a 3.25 inch stroke and a 350 has a 3.48 inch stroke.

The newest option is 26 years old, so it would not be wise to assume the heads, crank, rods or pistons are original.

You have a typical large journal 4-inch block. The heads and crank might make it special and might not. Most likely its a generic 350.

Thanks to all for all the great info.
Hopefully one day I can return some favours

My vote is for a 350. The 302's and 327 industrials are both very rare. That's a popular casting number for race engine, all of mine shared that casting. If you can take it apart, look under the timing cover for the numbers 010 or 020. These are indicators that extra tin or nickel were added to the cast iron, making for a very strong block.

thats the same casting on my block. 2 bolt main 4" bore. I've got aluminum heads from an L98 corvette on mine however.