2 or 4 bolt main blocks
Thread Starter
Racer
Joined: Oct 2001
Posts: 412
Likes: 0
From: Monroe North Carolina
2 or 4 bolt main blocks
I have a 1973 with an L-48 motor. Does anybody know if it is a 2 bolt or 4 bolt main block? Any help is needed?
And also what is the difference in the two?
And also what is the difference in the two?
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Re: 2 or 4 bolt main blocks (Corvettelvr73)
Te L-48 is typically a 2-bolt motor. Not that this should worry you as the two bolt can handle a whole heck of a lot more than most people give it credit for. IMO, for a street motor the only advantage to a 4 bolt is bragging rights when bench racing :lol:
Race Director
Joined: Apr 1999
Posts: 15,134
Likes: 477
From: NM
Re: 2 or 4 bolt main blocks (Corvettelvr73)
I have a 1973 with an L-48 motor. Does anybody know if it is a 2 bolt or 4 bolt main block? Any help is needed?
And also what is the difference in the two?
And also what is the difference in the two?
As has been said, the 2-bolt should hold up okay for most any street application. Now if you are running NOX or supercharger you will probably want to go with 4-bolt mains.
tom...
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
Re: 2 or 4 bolt main blocks (Corvettelvr73)
Anyone have any ideas how the GM GW 350 compares to the L-48 block? I know the LM-1 has a 4-bolt main, but not sure about crank and rods and all the rest.
Le Mans Master
Joined: Aug 2000
Posts: 9,662
Likes: 7
From: Semper ubi, sub ubi
Cruise-In VI Veteran
Cruise-In VII Veteran
Re: 2 or 4 bolt main blocks (Pacin'California)
Standard truck parts in the GM crate motor, cast crank, rods and pistons. At least that's what the guy at GM told me. ZZ-4 has forged crank.
Burning Brakes
Joined: Dec 2000
Posts: 795
Likes: 0
From: Madison MS
Re: 2 or 4 bolt main blocks (Smokehouse69)
I have heard of some L-48s that had 4 bolt mains. Here's the way the story goes:
If there was a shortage on the line, they would substitute L-82 blocks and use L-48 internals. But they NEVER were allowed to substitute an L-48 2 bolt block for an L-82. I have a feeling that there weren't that many 4 bolt main L48s though.
dl
If there was a shortage on the line, they would substitute L-82 blocks and use L-48 internals. But they NEVER were allowed to substitute an L-48 2 bolt block for an L-82. I have a feeling that there weren't that many 4 bolt main L48s though.
dl
Race Director
Joined: Apr 1999
Posts: 15,134
Likes: 477
From: NM
Re: 2 or 4 bolt main blocks (dladd74roadster)
I have heard of some L-48s that had 4 bolt mains. Here's the way the story goes:
If there was a shortage on the line, they would substitute L-82 blocks and use L-48 internals. But they NEVER were allowed to substitute an L-48 2 bolt block for an L-82. I have a feeling that there weren't that many 4 bolt main L48s though.
If there was a shortage on the line, they would substitute L-82 blocks and use L-48 internals. But they NEVER were allowed to substitute an L-48 2 bolt block for an L-82. I have a feeling that there weren't that many 4 bolt main L48s though.
tom...
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