2 or 4 bolt engine?
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Joined: Jan 2004
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From: Edwards CA
2 or 4 bolt engine?
I was wondering what is the easiest way to tell if you have a 4 bolt or 2 bolt engine, the reason is I would like to get a 383 crate engine but it is hard to find them for 2 bolts which is what I think I have. It's a '79 with the stock 350 auto with California emissions (or at least it is suppose to) Thanks for the help.
Drifting
Joined: Jun 2003
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From: Upstate South Carolina
Most 70s Corvette 350s had a 3970010 block. The block came with both a 2-bolt and 4-bolt main depending on year and engine. Most high performance (LT-1, L-82) were 4-bolt with the base engine being 2. Yours is probably 2-bolt.
Safety Car
Joined: Jul 2001
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From: York PA
Originally Posted by l979 Corvette
I was wondering what is the easiest way to tell if you have a 4 bolt or 2 bolt engine, the reason is I would like to get a 383 crate engine but it is hard to find them for 2 bolts which is what I think I have. It's a '79 with the stock 350 auto with California emissions (or at least it is suppose to) Thanks for the help.
2 bolt or 4 bolt refers to the number of bolts on the main caps. Any parts that fit a 2 bolt will fit a 4 bolt and vice versa. (with the excption of the main caps) The only way to be sure what you have is to pull the oil pan and look. However you probably have a 2 bolt, if you have a L-82 you might have a 4 bolt but I'm not positive about that. The 4 bolt is stonger than the 2 bolt, but unless you are going to build an engine an plan to spin it above 6000 rpms regularly, a 2 bolt will be fine on the street. 
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Le Mans Master
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From: Little Rock AR
Not sure but here is something to check....Look at the boss on the rear of the block at the top center. See if it is just a hole or if it is tapped with threads. If threaded, you probably have a 4 bolt block.
-Mark.
-Mark.
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Joined: Sep 2004
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by Kalway
I believe all 350s in Corvettes up to 1981 were 4 bolt. At the top of my head the only 2 bolt was the L-81.
my l48 in the 77 was a 2 bolt
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From: NM
Originally Posted by Kalway
I believe all 350s in Corvettes up to 1981 were 4 bolt. At the top of my head the only 2 bolt was the L-81.
tom...
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From: Dickinson (Houston) Texas