Vannin' Home Forums Chevy General Discussion 350 4 bolt main

I do not speak Chevy very well. How do you tell if an engine is a 4 bolt main 350 from the outside... I was going to send my endoscope through the oil drain hole, except it will not fit.....So much for the proctology approach

if it is a pre-85 look at the back of the block near the top. Look for a long bank of #'s the number you are looking for is 3970010. That is the block you want to build. let me know what #'s are on your block and I'll tell you what motor you have.

Thanks Chooie. I will do that when I get home tonight... However do not need to build it. It is supposed to be a 300hp 350 4 bolt crate motor with 5000 miles on it

No worries, I have one sitting waiting on cash. I want to make a 383 out of it. It is not hard to check if the numbers done help. Just take off the oil pan and see how many blots hold the main caps around the crankshaft. That is where they get Two-bolt or Four-bolt mains from. An upper and a lower on each side of the crank on each main cap is likly to hold up to higher R.P.M.'s. You can modify two-bolt mains but it's just not the same.
They sell aftermarket main caps that claim super high rpm allowances but you really dont need most of those until you are in the 600-750 hp range.

I don't see any Chevy's listed on your signature. Glad to see that you've seen the light and found Chevy's! Welcome to the real world, where horsepower is plentiful, and parts are abundant. Let me know what you find.

I don't own the Chevy. I bought a complete and running 77 S/b no windows that is rough for the motor for one of our club members who has a tired 305 in it. Wanted to verify before I pulled the motor out of it. I will part out the rest or ????????? If you want HP I have a 550 hp , 409 stashed for my retirement fund I am a Ford man, but always end up with a dodge for some reason.

just pull the pan ! it is the best way

Chooie, The casting number shows as 10243880 which a Chevy site It says it is 95-00 Vortec Gen 1 Crate motor, with a ZZ4 roller cam, one piece rear seal... Here is the kicker. It could be a 2 or 4 bolt main. DUH !!!!!!! I am back to square 1 again. Since it does have a one piece rear main seal, I do not want to mess with the pan while it is in the van........ I guess I need a smaller Endoscope, or lots of Vaseline to see if it is a 4 Bolt main.............lol

Doc,on the passenger side of the block behind the alternater there should be a small ledge. There should be a number stamped onto that ledge.That munber will tell you what the engine is.The year and what the engine came out of.Itis a a little hard to find.Take that number to the library and find a Chiltons manual or a Motors manual there is a secton for block I.D numbers.Good luck ......Wookee