L48 Rebuild
Thread Starter
Racer
Joined: Sep 2010
Posts: 259
Likes: 1
From: Mt Airy, NC
L48 Rebuild
I have a 78 Vette with stock L48. I want to end up with around 375hp. Could or should I keep my 2-bolt main block? This will not be a strip car, I would prefer a 4-bolt main block but thats not whats in car and was trying to decide whether to rebuild what I have or start from scratch. Please help with info...
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
There are two parts to the question; I'll try to hit both
375HP is well within the capabilities of a GEN I 2-bolt main block with no worries at all.
However, consider that if originality is important you may be better off setting that original L48 aside and just building a fresh engine, or buying a crate.
375HP is well within the capabilities of a GEN I 2-bolt main block with no worries at all.
However, consider that if originality is important you may be better off setting that original L48 aside and just building a fresh engine, or buying a crate.
Drifting
Joined: Nov 2007
Posts: 1,701
Likes: 272
From: New York
I am assuming you want and numbers matching car. So you are reluctant to modify the stock motor to get the 375 HP. You could always lift out the original numbers matching engine and replace it with whatever you want. I purchased a Chevy 383ci / 450hp Long Block and could not be happier. Engine out on day one, engine in on day two, with a little help from two friends.
If the time comes to sell, replace the numbers matching motor and sell the crate motor.
If the time comes to sell, replace the numbers matching motor and sell the crate motor.
Drifting
Joined: Dec 2005
Posts: 1,360
Likes: 3
From: NORTHEAST
I am assuming you want and numbers matching car. So you are reluctant to modify the stock motor to get the 375 HP. You could always lift out the original numbers matching engine and replace it with whatever you want. I purchased a Chevy 383ci / 450hp Long Block and could not be happier. Engine out on day one, engine in on day two, with a little help from two friends.
If the time comes to sell, replace the numbers matching motor and sell the crate motor.
If the time comes to sell, replace the numbers matching motor and sell the crate motor.
Thread Starter
Racer
Joined: Sep 2010
Posts: 259
Likes: 1
From: Mt Airy, NC
No concern
I'm not really concerned about having a matching number motor as the 78 (with maybe the pace car edition as the exception) is not a very high price bringing stock model. That being said, my goal for re-using the L48 was only that I have it and I know what I've got. I'm kinda scared of getting scammed on a crate motor and I didn't know if there would be price benefit to rebuilding what I have. I know most of what the engine has will need to be replaced to achieve 375+ hp so my biggest concern was the 2-bolt mains handling that much hp.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Fair enough. 375HP is well within reasonable llimits.
If you're still worried about it, you can switch from bolts to studs - but this will require an align-hone and honestly it's not needed.
Someone will no doubt try to scare you into thinking you're way over the limit - but there many, many 2-bolt engines running around (some that I've built) with well over 400 HP and have many hard runs on them.
If you're still worried about it, you can switch from bolts to studs - but this will require an align-hone and honestly it's not needed.
Someone will no doubt try to scare you into thinking you're way over the limit - but there many, many 2-bolt engines running around (some that I've built) with well over 400 HP and have many hard runs on them.
Drifting
Joined: Nov 2007
Posts: 1,701
Likes: 272
From: New York
I would have to agree, that most 375 hp motors you probably will not rev it past 5800. Plus the fact that you said you are not going to race, I would expect this motor to do well.
To get to around the 375 mark, I would (and did) buy and Edelbrock RPM Performer cam, and intake manifold. Personal preference on my part is a set of AFR 195 cc head (as apposed to and Edelbrock RPM Performer heads). Add a good set of Headers and carb and you will be in the 375 to 400 hp range.
To get to around the 375 mark, I would (and did) buy and Edelbrock RPM Performer cam, and intake manifold. Personal preference on my part is a set of AFR 195 cc head (as apposed to and Edelbrock RPM Performer heads). Add a good set of Headers and carb and you will be in the 375 to 400 hp range.
Drifting
Joined: Nov 2007
Posts: 1,701
Likes: 272
From: New York
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