350 chevrolet

how can you tell the difference between a 350 2-bolt main and a 350 4-bolt main by using the engine code.

 

Simple; you can't. The one and only way is to remove the pan and look.

 

The information on this website has been accurate for me: http://www.nastyz28.com/sbchevy/sblock.html Hope it helps!

 

im guessing here but it seems i heard somewhere that 4 bolt blocks have a tapped and plugged oil pressure hole above the timing chain cover??? or maybe they all are like that?

 

The only way to tell for sure is to pull the pan.

But.....in general, not always, you'll find 4 bolt mains on 3970010 casting number blocks in 4bbl equipped pickup trucks from the 70s, and you'll find them in the late 60s-early 70s Corvette 350 engines, even the low perf ones, and in the high perf 350s in Vettes and Camaros up thru 74.

Of course you have to look up the codes and figure out if the engine in question was used in one of these applications. I have some books that have codes, and they're available on the internet if you look for a while.