C3 Tune engine or swap it?
Thread Starter
1st Gear
Joined: Jun 2023
Posts: 1
Likes: 0
C3 Tune engine or swap it?
Hey everyone I own a 1978 C3 with a stock Chevy small block 350. I want to put a lot more power into the car I was looking at an ls2 swap but that runs up the price tag way too high for me. I want to keep the purchase of the engine price at around $5k if I decide to do an engine swap. My question is that should I try to do an engine swap or is better if I just try to tune the stock engine? I was looking at engines and there was a ls 5.3 available but others also talked about a stroker 383 is better for a swap. I don't know too much about engines or which ones are "better". Just looking for guidance if I should swap my engine to get an overall faster and more powerful C3 or just tune the existing engine.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
Hey everyone I own a 1978 C3 with a stock Chevy small block 350. I want to put a lot more power into the car I was looking at an ls2 swap but that runs up the price tag way too high for me. I want to keep the purchase of the engine price at around $5k if I decide to do an engine swap. My question is that should I try to do an engine swap or is better if I just try to tune the stock engine? I was looking at engines and there was a ls 5.3 available but others also talked about a stroker 383 is better for a swap. I don't know too much about engines or which ones are "better". Just looking for guidance if I should swap my engine to get an overall faster and more powerful C3 or just tune the existing engine.
Melting Slicks
Joined: Jun 2016
Posts: 2,979
Likes: 332
From: Woodinville WA
BluePrint Roller Cam Crate engine and just tell them that you need a short intake that will clear a Corvette hood. (Or if you've got an L82 aluminum intake, tell them you don't need an intake at all).
Adam
Adam
Race Director
Joined: Nov 2006
Posts: 13,195
Likes: 7,795
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Here's the deal,. You want a LOT more power. But your on a beer budget in the world of fast cars.
First, WHICH 350 engine do you have? L82? Good bones in it for a hot build. 4 bolt mains, quality crank, rods and pistons.
Or L48? 2 bolt mains. Lower quality crank and rods (Although not junk).
What are you starting with?
How do you plan to put a LOT more power to the ground?
Through the factory stock transmission, diff, half shafts and axles? If so your going to be very disappointed.
There is a lot more to it than just stuffing in a engine. Everything behind that engine will need beefing up as well.
You say you want a LOT more power.
I say you need a bigger budget.
Perhaps start by tuning what you have and try to get the best power out of what you have.
Then spend some time doing more research on what it really takes to make a lot of power in a C3. And what breaks, and what it costs.
Welcome to the forum! Lots of answers here. Take your time and enjoy your car!
First, WHICH 350 engine do you have? L82? Good bones in it for a hot build. 4 bolt mains, quality crank, rods and pistons.
Or L48? 2 bolt mains. Lower quality crank and rods (Although not junk).
What are you starting with?
How do you plan to put a LOT more power to the ground?
Through the factory stock transmission, diff, half shafts and axles? If so your going to be very disappointed.
There is a lot more to it than just stuffing in a engine. Everything behind that engine will need beefing up as well.
You say you want a LOT more power.
I say you need a bigger budget.
Perhaps start by tuning what you have and try to get the best power out of what you have.
Then spend some time doing more research on what it really takes to make a lot of power in a C3. And what breaks, and what it costs.
Welcome to the forum! Lots of answers here. Take your time and enjoy your car!
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
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
Instructor
Joined: Sep 2022
Posts: 125
Likes: 29
From: Poconos
Hey everyone I own a 1978 C3 with a stock Chevy small block 350. I want to put a lot more power into the car I was looking at an ls2 swap but that runs up the price tag way too high for me. I want to keep the purchase of the engine price at around $5k if I decide to do an engine swap. My question is that should I try to do an engine swap or is better if I just try to tune the stock engine? I was looking at engines and there was a ls 5.3 available but others also talked about a stroker 383 is better for a swap. I don't know too much about engines or which ones are "better". Just looking for guidance if I should swap my engine to get an overall faster and more powerful C3 or just tune the existing engine.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,181
Likes: 9,315
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
what is your timng set too? if its stock setting investigate Lars tuing papers, get it up to about 16* base then see what your at for all in with mechanical advance added to that base number. It will feel like you just gavve her some more horsepower.
If you browse Summit Racing you can find a motor in your budget with some good horsepower. Its cheaper to buy than build currently but you should buy before the economy gets to soft and the prices get to high
heres some but you will need an intake that will fit under the hood and you can reuse your dizzy and carb if you get it rebuilt, and reuse the starter. Maybe a new aluminum water pump and headers
https://www.summitracing.com/search/...=crate%20motor
If you browse Summit Racing you can find a motor in your budget with some good horsepower. Its cheaper to buy than build currently but you should buy before the economy gets to soft and the prices get to high
heres some but you will need an intake that will fit under the hood and you can reuse your dizzy and carb if you get it rebuilt, and reuse the starter. Maybe a new aluminum water pump and headers
https://www.summitracing.com/search/...=crate%20motor
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
Taking into account your post, I recommend you look for a junkyard that has
eng/trans combo's complete with ecu.
What motor and year will be the hard choice but you are lucky because for
25 + years gm has made good motors/trans that will fit.
Look up performance cars like Camao, TransAm, hell, even trucks.
eng/trans combo's complete with ecu.
What motor and year will be the hard choice but you are lucky because for
25 + years gm has made good motors/trans that will fit.
Look up performance cars like Camao, TransAm, hell, even trucks.
Race Director
Joined: Mar 2017
Posts: 11,931
Likes: 4,497
From: Virginia
If you car is an automatic, fix that first.
You can get a lot of performance back just from a tune. Perhaps enough to keep you happy. Email @lars for his tuning papers. There are lots of threads.
If you pull that engine out, an LM7 5.3 swap can be done for cheap. You'll have to change some things, but most of that is stuff you'd have to change for an EFI conversion anyway. Don't waste time with another SBC unless you get it for free.
You can get a lot of performance back just from a tune. Perhaps enough to keep you happy. Email @lars for his tuning papers. There are lots of threads.
If you pull that engine out, an LM7 5.3 swap can be done for cheap. You'll have to change some things, but most of that is stuff you'd have to change for an EFI conversion anyway. Don't waste time with another SBC unless you get it for free.
Le Mans Master
Joined: Oct 2010
Posts: 6,930
Likes: 845
From: melbourne florida
2023 C3 of the Year Finalist - Modified
Last edited by 7t9l82; Jul 1, 2023 at 10:02 AM.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
To the OP....determine the condition of your engine and what you have......
Jebby
Burning Brakes
Joined: Jan 2003
Posts: 961
Likes: 275
From: Frederick MD
To help you determine what motor you have in the car I offer this up. On the front of the block on the passenger side there is a small pad about 1/2 the size of a playing card that is part of the block deck where the cylinder head bolts down. Clean that up good. That will tell the pedigree of the engine that is in the car. Might not be the original bullet regardless of what you’ve been told/think. If there is nothing there then it’s likely somebody has been into the motor and it’s been decked. That’s ok. Take a look at the rear bell housing area of the block. There should be a casting number back there as well. If it’s a L82 and the bottom end is healthy a top end kit with headers and other supporting mods would be worth 150ish hp.
Instructor
Joined: May 2018
Posts: 248
Likes: 11
Short Block Rebuild.
I had my L82 block and internals inspected by a reputable engine builder. Everthing checked out so the cyclinders were re-honed, rods resized, along with the usual rebuild. I picked out a comp street cam that will give me good midrange torque with a 110 LSA. I bought a set of Edelbrock E street heads and had them checked out, Spring Pressures were way too strong so had them changed out to suit the 490 lift cam. I was told that if I had used these heads as is I would have wiped out my engine at startup. I can't over emphasize the need to have new heads properly matched to an after rmarket cam.
Short Block rebuild $2300
E Street Heads $1300
New Clutch/ Parts $500
Rebuild Entire Front Suspension $550
Radiator Rebuild $150
Water Pump $65
Balancer $75
Misc Parts paint hardware $500
Blood Sweat and sore joints...No Charge
Short Block rebuild $2300
E Street Heads $1300
New Clutch/ Parts $500
Rebuild Entire Front Suspension $550
Radiator Rebuild $150
Water Pump $65
Balancer $75
Misc Parts paint hardware $500
Blood Sweat and sore joints...No Charge