Need recommendations for engine upgrades
Thread Starter
6th Gear
Joined: Feb 2012
Posts: 6
Likes: 0
Need recommendations for engine upgrades
I recently inherited a 75 with the L48 engine, not sure what transmission but I believe it is all original. Besides basic repair work to keep it running, I believe everything on the car is original. It has been sitting for awhile so I plan to have the engine and transmission pulled and rebuilt.
I figured while doing this, I'd like to soup up the engine a bit. I will not be doing the work, a shop will. I am looking for ideas on things I can ask for to be added or changed out to help increase horsepower, torque, etc...
My overall budget is around $10,000. I'd rather not spend all of it on the engine and tranny as I'd like to do some other restoring of the car as well.
Thanks in advance for any suggestions.
I figured while doing this, I'd like to soup up the engine a bit. I will not be doing the work, a shop will. I am looking for ideas on things I can ask for to be added or changed out to help increase horsepower, torque, etc...
My overall budget is around $10,000. I'd rather not spend all of it on the engine and tranny as I'd like to do some other restoring of the car as well.
Thanks in advance for any suggestions.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
The L48 really needs more than a couple of simple bolt-ons during rebuild to wake it up, so you might want to consider just setting it aside and installing a decent performance crate engine from a reputable source. JMO
Melting Slicks
Joined: Mar 2001
Posts: 2,174
Likes: 56
From: Clarence N.Y.
engine
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
Look at Jegs or Summit for some references after your shop gives you a quote. For around $4K you can have a 400HP engine delivered (eg. http://www.jegs.com/i/Blueprint-Engi...oductId=761056). That will give you plenty of cash and a LOT more time to work on the tranny and chassis to handle all that power!
Burning Brakes
Joined: Apr 2007
Posts: 1,039
Likes: 62
From: Kona Hawaii
Good advice given already.I have a 76 L48 that I upgraded.If I know then what I know now I would've gone the crate engine route.You'll be ahead with a good crate engine and install an OD trans while your at it.Having a 6spd manual is way more enjoyable to drive then a 3spd auto.
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
Getting the right combination is what you want. The motor,tranny and rear end all have to work well together. The motor itself has to have matched parts too. If you haven't spent the last 10 years reading Hot Rod or Super Chevy then a crate may be a good idea.
For the motor you need a set of small chamber heads to boost compression, a cam that has a low power band, an aluninum intake and headers. $3k ish with lifters gaskets and stuff.
If you get a cam that sounds like you got a cam then you probably want a different torque converter $200
Then do you keep those highway gears and switch to a 700-r4 so you can spin the tires or change the rear end or both.
Torque converter and gearing will make less HP feel more fun.
For the motor you need a set of small chamber heads to boost compression, a cam that has a low power band, an aluninum intake and headers. $3k ish with lifters gaskets and stuff.
If you get a cam that sounds like you got a cam then you probably want a different torque converter $200
Then do you keep those highway gears and switch to a 700-r4 so you can spin the tires or change the rear end or both.
Torque converter and gearing will make less HP feel more fun.
Race Director
Joined: Mar 2016
Posts: 14,325
Likes: 8,129
From: Napa Valley California
Do your research on any create motor.
Make sure they are using "new" top quality parts and look for things like, forged pistons, forged cranks, rods, etc that are name brand components.
Watch out for comments like "reconditioned", "as good as", assembled in Mexico or China, etc.
If you purchase a cheap create motor, you get cheap.
You really need to do your research and just don't purchase one with a good warranty.
Also read the full warranty.
Most require that you return the motor to the manufacturer for them to diagnose the cause for failure before any warranty repairs are made.
I purchased a create motor from a well known builder about ten years ago.
The engine cradle failed during shipping and the motor was bouncing around inside the shipping create during shipment.
The manufacturer fought with the shipping company for over one year while I had a new battered motor sitting in my garage I couldn't use.
Be careful.
Make sure they are using "new" top quality parts and look for things like, forged pistons, forged cranks, rods, etc that are name brand components.
Watch out for comments like "reconditioned", "as good as", assembled in Mexico or China, etc.
If you purchase a cheap create motor, you get cheap.
You really need to do your research and just don't purchase one with a good warranty.
Also read the full warranty.
Most require that you return the motor to the manufacturer for them to diagnose the cause for failure before any warranty repairs are made.
I purchased a create motor from a well known builder about ten years ago.
The engine cradle failed during shipping and the motor was bouncing around inside the shipping create during shipment.
The manufacturer fought with the shipping company for over one year while I had a new battered motor sitting in my garage I couldn't use.
Be careful.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Safety Car
Joined: Dec 2009
Posts: 4,528
Likes: 444
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
can add bigger roller cam and vortec intake and hi-lift springs&retainers And have local machine shop finish the fuel pump mount. Read it entirely under $1600 delivered .
https://www.ebay.com/itm/GM-OEM-NEW-...nA85:rk:1:pf:0
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
That motor is Not marketed as a hi-po motor with lotsa hype … it's marketed as a OE replacement for a truck.
GM doesn't publish HP spec for replacement motors as that's part of hi-po ad campaign
No need to publish replacement motor HP spec as it's the same as OE and That is/was published.
If GM published all the tips & specs & potential this replacement motor has... that might help defeat the efforts of their Performance marketing crew.
This replacement motor is essentially a 350HO … but this has OE roller cam&lifters… and it's about $1000 LESS!
Local machine shop can finish pump mount for $100.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Absolutely, slickest fix I see is swap to GM LT4 "Hot Cam" & LS6 springs & maybe 1.6:1 rockers. That's basically what yearone & blueprint do for around 400hp.