Sorry...
do i have a 4 bolt main
Safety Car
Joined: Nov 2008
Posts: 3,720
Likes: 555
From: Seattle Washington
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.
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
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
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
Melting Slicks
Joined: May 2007
Posts: 2,415
Likes: 154
Le Mans Master
Joined: Oct 2007
Posts: 7,454
Likes: 977
From: RI, Now Franklin/Nashville TN
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.
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Drifting
Joined: Mar 2011
Posts: 1,886
Likes: 9
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.
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 6,664
Likes: 162
From: columbia city in
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.
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
Scott
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
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.
Having a car on the sideline because it's waiting on its original engine to be rebuilt is wasted seat time.
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
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
Le Mans Master
Joined: Oct 2010
Posts: 6,937
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
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.
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.
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
I mean, didn't the foundry do that to the 4-bolt main blocks?
Steve
Melting Slicks
Joined: May 2007
Posts: 2,415
Likes: 154
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.