terry82

Can anyone tell me, with out droping the pan on my 1982 if I have a 2 bolt or a four bolt main.

qwank

if it's the stock engine it's 2 bolt

Gale Banks 80'

There are many clues to say it is or isn't but the only way to know for sure is to see the main caps. You can buy a Camera that would go threw the Oil pan Drain pretty darn cheap now that plugs into Your PC. Or You might be able to rent one.

scottyp99

Do I win something if I guess right?

As far as I know, there is no sure way to tell without looking. As my Granpappy in Maine used to say, "Hard tellin', not knowin'." Sorry, Charlie, only the best tuna get to be Starkist.

Scott

L88Plus

If the engine is original - check for the last 6 digits of the VIN on the deck stamping just in front of the passenger side head - it's a 2-bolt, like qwank stated.

CaseyJones

Sorry...

PAmotorman

if it happens to be a 4 barrel carb truck block it will be a 4 bolt block. check the stamp pad to see what you have.

jb78L-82

I believe the last 4 bolt mains as advertised were the 1980 L-82. The L-48, L-81 and 82 crossfire were all 2 bolt mains. Checking the stamp code is not a sure fire way to know since GM was known to substitute blocks if they ran short of a particular engine block., Would they substitute a truck block for an 82 one, not sure, but there are L-48's with 4 bolt mains and some L-82's with 2 bolt mains. I just checked mine today after pulling the motor and yes my L-82 is a 4 bolt main-excellent.

billla

There is no way to be positive without looking at the caps, period.

gcusmano74

Don't worry too much about it. Years ago, I think it was David Vizard who said that, a CORRECTLY SET UP bottom end on a Chevy smallblock with a two bolt main could be reliable to 500 HP. I'd guess if you are looking to build more than 400 HP, use ARP main bolts, just to be safe.

Jim78SA

You can always splay the mains and block. Creating a stronger than 4 bolt. You might as well if you are rebuilding anyway.

terry82

i may have a chance to buy a very cheap priced four bolt main block that i could build then put in my car .if i already have a 4 bolt ,i will just build the block i have .but it sounds like i should buy this new block [$75.00]Thanks for all replys.

MrJlr

100%

Jim78SA

I would buy a splay kit and splay the block you have. Stronger than the four bolt.

scottyp99

If it passes magnaflux and still has some meat in the bores, that sounds like a pretty good deal.

Scott

L88Plus

I'd have that $75 block checked and if it's good, build it. That would let you leave the original alone until time to swap out.
Having a car on the sideline because it's waiting on its original engine to be rebuilt is wasted seat time.

Cavu2u

Hey Terry,

If you don't buy it, I will! 75 bucks!

And yeah, my 383 build started out as a '76 C10 4-barrel mill.
Also, it's valve cover hold down tabs are of the long type. If these long types are only factory associated to 4-bolt main engines, I don't know. But would be interested to see if this is common with other 4-bolt owners here.

Steve

7t9l82

i have used the splayed caps and they work very well and are very stable.
there is a school of thought that may have merit and that is you weaken the " stronger " part of the block when you drill and tap into it. personally i don't think it would make that much difference. but i do like 4 studs as opposed to 2 bolts and 2 studs.

Cavu2u

I don't either.

I mean, didn't the foundry do that to the 4-bolt main blocks?

Steve

PAmotorman

back in the day of using 327 blocks for racing we machined the bottom of the 3 center main caps flat and then using longer allen cap screws installed 7/8" X 7/8" cold rolled steel straps across the main caps. the weakest part is the caps themselves because without the straps the caps would crack as the force on the caps is downward.