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I would like to get 300 to 350 horsepower from the L48 in my car. I don't want to go with a crate engine because of my budget. I have about $2500 to spend. I recently sold a 99 and would like to get about the same hp as that did. I have a basic idea on what I want to do. I just want to see what others would do.
How deep are you willing to go into the engine? A head, cam and intake swap will do wonders for it. The Edelbrock package 2022 would fit the bill but I would change the cam, the ones in their packages are really old technology but should be easy on the valve train.
My L48 is now a 350 hp 390 Tq motor done by my local engine builder. Its his own version of a GM crate motor. 2 bolt main 9.0-1 compression, Dual pattern comp hydraulic cam non roller. Heads are warmed over 882 truck heads, 1.94 intake 1.60 exhaust. intake is an Eddy dual plane with a 1406 eddy carb.
I dropped off a block crank rods oil pan intake carb and Distributor. He supplied the rest. Put the motor on the dyno, broke in the cam, seated the rings and made some pulls. $3600.00 out the door tax paid. Comes with 6 months/ 6000 mile warranty
The following link is to a thread I posted with some rear wheel chassis dyno data from my build up. The cam gave the largest power increase but I doubt the results would have been the same if the other modifications were not in place.
It is important to note that since I finished the motor, I had to upgrade the torque converter to a 2800 stall and switched the rear end to a 3.55 unit in order to make the car operate in the cams power band.
Chevy High Performance did a series years ago about the Vortec heads and matched it with a comp cam xe268h cam. It's going to take both components and new heads can get pricy quick. You may find something interesting on craigslist...
use your old engine as a core and build it to a L-79`s specifications and you engine is still all stock appearing with its correct numbers...the result, 350hp
Jegs has a couple of crate engines with what you're looking for in your price range and are offering free shipping.
I myself would build the engine into a 383. I loved the feel in my 77 many years ago.
Cam in the 220ish range @.050 FT or hyd roller take your pic. Big price difference. Even throwing an Isky 270 mega cam at it would work.
Good used dual plane intake
650+-carb
1-5/8 primary headers
Recurve your distributor
roller rockers possibly pushrods
Gaskets fluids
Should creep up on 350 at the tire Id bet and be close to budget. Perhaps a touch over but youll love how it runs.
Location: So Cal- - Defend your ideas with facts. Not personal attacks.
The L48 is very similar to the GM crate 350".
You really should review the series of acticles by Chevy Hi-Performance on a GM crate 350". This should give a good idea of it takes to get a low compression 350 to over 400hp. Take a look: http://www.chevyhiperformance.com/te...ild/index.html
I really don't want to pull the motor from the car. I will tear it down to the short block and add heads, cam, intake and carb. And headers. I am going to order a set of Hookers probably tomorrow.
Do your self a favor, don't skimp on the heads, there are many good heads out there & there are tons of cheap heads, nothing out there in the line of good cheap heads. I favor afr, great flow with hogging out the ports. they really can't be beat in the 23 degree head category.
Cam in the 220ish range @.050 FT or hyd roller take your pic. Big price difference. Even throwing an Isky 270 mega cam at it would work.
Good used dual plane intake
650+-carb
1-5/8 primary headers
Recurve your distributor
roller rockers possibly pushrods
Gaskets fluids
Should creep up on 350 at the tire Id bet and be close to budget. Perhaps a touch over but youll love how it runs.
Great advice! Look at the Howards cams at Summit. $500 gets you a billet core retro hydraulic roller and lifters. AFR heads need the +.500 lift of a roller cam to get the full benefit of the heads.
Great advice! Look at the Howards cams at Summit. $500 gets you a billet core retro hydraulic roller and lifters. AFR heads need the +.500 lift of a roller cam to get the full benefit of the heads.
I was thinking Performer RPM heads and definitely a roller hydraulic cam. I don't know what size yet. Also a performer intake and probably a 750 vacuum secondary holley. I am ordering the headers today. I also guess I will keep the HEI.
No problem. I remembered a forum member a few years back that had major problems with no resolution so I did a quick search.
Being that I am 2k miles away from Phoenix, that could have been a disaster for me. Their website is very misleading then. I will be looking at the GM site again and just go with them.
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Get my L48 to 350 horsepower.
Take a look: 
