5.3L into my 73?
Thread Starter
Instructor
Joined: May 2010
Posts: 118
Likes: 0
From: conway arkansas
5.3L into my 73?
I have been having trouble out of my old 454 and now have the opportunity to buy a 2007 truck 5.3L with computer and harness fairly cheap from a friend of mine. I'm wondering if anyone has done this swap before? If so how much trouble is it? What is required? Will it mate to the muncie?
Thanks!
Thanks!
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
What exactly you really wanting, cause if you're going through the trouble of an LS swap, would have to be an LS2 or 3 to make it worth while. Have you looked into the cost of having your 454 redone, as probably the easiest way. Another thing going with a smaller/lighter engine, is the front springs, as car could look like like its ready for lift off.
Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
There are no 2 LS engine swaps that are exactly the same. It will take you a few days to go through the whole swap thread but you will get a lot of different ideas on how to approach things like fuel system, cooling system, wiring, etc. that you won't find anywhere else. If you come up with something that no one else has thought of add it to the thread!
Rick B.
Rick B.
Race Director
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Here is a neat little story HOT ROD Magazine did on the 5.3 liter motor. Give it a short read. I was impressed.
5.3 LS Motor
5.3 LS Motor
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
I did a 6.0 LQ9 in my 68 corvette, I've also got an 05 5.3 mated to a Muncie in my 72 442. What's your rear end ratio? These motors are great at low rpm so an OD trans would really take advantage of the SFI head design, etc.
If you want full details, let me know all the details on your car.
If you want full details, let me know all the details on your car.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Safety Car
Joined: Mar 2009
Posts: 3,558
Likes: 4
From: Oakland California
Do not underestimate the 5.3. You can squeeze good power out of these engines. Just an example, LM7, 317 Heads(LQ9), turbo, meath injection, 600 RWHP
! That's all on a stock bottom end! I had an LM7 and was planning this build, but ending selling it because I had to piece that thing together, so I just sold it and am now looking for a complete LS1, and T56. I actually just received part of my fuel system for my swap(hose, fitting, fuel line). My plans are to gather the small things and install them on the car for when I find the perfect LS1/T56 candidate for my swap. I have been doing lots of research on the topic.
! That's all on a stock bottom end! I had an LM7 and was planning this build, but ending selling it because I had to piece that thing together, so I just sold it and am now looking for a complete LS1, and T56. I actually just received part of my fuel system for my swap(hose, fitting, fuel line). My plans are to gather the small things and install them on the car for when I find the perfect LS1/T56 candidate for my swap. I have been doing lots of research on the topic.
Drifting
Joined: Oct 2008
Posts: 1,496
Likes: 6
From: springfield ohio
Your replacing a 454? With a 5.3? Personally I would rebuild the 454, it will be cheaper in the long run and I feel you would be much happier in the end, with the results and your wallet.
What would you have in a rebuilt 454 $1000 to $1500? My vote is to stay with the 454. If you do chose the LS route, I wouldn't do anything less than a 6.0, I don't think a stock 5.3 would feel much different than a stock small block C3.
I am finishing an LS2 swap and can tell you first hand, it's expensive.
Riggs
What would you have in a rebuilt 454 $1000 to $1500? My vote is to stay with the 454. If you do chose the LS route, I wouldn't do anything less than a 6.0, I don't think a stock 5.3 would feel much different than a stock small block C3.
I am finishing an LS2 swap and can tell you first hand, it's expensive.
Riggs
Melting Slicks
Joined: Nov 2002
Posts: 2,231
Likes: 7
From: Fort Pierce Florida
Your replacing a 454? With a 5.3? Personally I would rebuild the 454, it will be cheaper in the long run and I feel you would be much happier in the end, with the results and your wallet.
What would you have in a rebuilt 454 $1000 to $1500? My vote is to stay with the 454. If you do chose the LS route, I wouldn't do anything less than a 6.0, I don't think a stock 5.3 would feel much different than a stock small block C3.
I am finishing an LS2 swap and can tell you first hand, it's expensive.
Riggs
What would you have in a rebuilt 454 $1000 to $1500? My vote is to stay with the 454. If you do chose the LS route, I wouldn't do anything less than a 6.0, I don't think a stock 5.3 would feel much different than a stock small block C3.
I am finishing an LS2 swap and can tell you first hand, it's expensive.
Riggs
The cost can get up there for any LS swap, but if you don't get too crazy you can do it pretty cheap. A 5.3L with transmission, computer, and harness shouldn't be much more then $1,000. You can have the harness rewired for $300 or you can do it yourself if you are capable. From there it is just engine mounts and figuring out the accessories and gauges. All of it can be done cheaply if you are handy and you have a bit of time. There are lots of options, information, and parts out there now. Still, I would budget for around $5,000 (including engine and transmission) just to be one the safe side.
Big blocks might be great for drag racers, nostalgia, or sound, but they are basically boat anchors compared to the LS engines of today if you are looking for a street motor.
Race Director
Joined: Dec 2007
Posts: 14,345
Likes: 4
From: Hartselle AL
St. Jude Donor '09
Check out this site.
http://www.yatesefi.com/lsx-swap-guide.html
The guy specializes in 5.3 conversions for hot rods.
http://www.yatesefi.com/lsx-swap-guide.html
The guy specializes in 5.3 conversions for hot rods.
Drifting
Joined: Aug 2005
Posts: 1,372
Likes: 4
From: Springfield VA
As said there are pros and cons with going from a 454 to a 5.3
pro:
Maybe better gas milage
faster
less weight
con:
could hurt resale
cost
time down to install it correct
If its a factory 454 I would leave it myself. Worse case sell it then buy a small block vette and gut it.
I thought about going to a LS setup but just to much headache and time down to get it right. I'm installing F/I on my small block and doing other things. I also have a driveable Corvette, not a show Corvette.
pro:
Maybe better gas milage
faster
less weight
con:
could hurt resale
cost
time down to install it correct
If its a factory 454 I would leave it myself. Worse case sell it then buy a small block vette and gut it.
I thought about going to a LS setup but just to much headache and time down to get it right. I'm installing F/I on my small block and doing other things. I also have a driveable Corvette, not a show Corvette.
Intermediate
Joined: Feb 2005
Posts: 41
Likes: 0
I agree with most of the comments above. The LS can a little more expensive, but the results are well worth it. The motor will get great fuel mileage compared to the gen 1 motor and the can make more power without having to interfere with reliability. My 6.0L makes over 500hp and torque at the crank (between 1000-6500 rpm)with just head and cam swap ( these motors have some serious flow). Not huge numbers for an LS motor but It's more than I need on the street. I could get that with a gen 1 motor as well, but reliability would not even be close unless I spent huge money on forged stuff. The stock Hoffman end on the LS is the best GM has ever produced. I was sold on the LS because of this info. I was going to go with a gen1 383, but could make the same power cheaper and more reliably. The parts to do the swap may or may not cost more. It depends on what you buy and if you can do some of the work. My swap will cost about the same. I'm doing most or all the work myself and without having to pay anyone I can purchase higher quality parts. I'm also going old school with a carb set-up. Makes it look like it almost belongs there.
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
Just an fyi. A few years ago I would not suggest anyone that does not have a great deal of mechanical ability trying an LS swap. But these days, pretty much everything is off the shelf, bolt on parts.
Here's a 5.3 with an LS1 intake connected to a muncie, pretty much exactly what you'll want.
Here's a 5.3 with an LS1 intake connected to a muncie, pretty much exactly what you'll want.
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
I'm with "riggs", as one thing changing a SB to an LS, but you're certainly not going to get the 454 torque with a smaller LS, unless you bolt a supercharger on it. If having the 73' BB redone, good opportunity changing some internals, to really get that thing roaring. I had a C5 6 speed LS1 Vette, and can’t say I was really impressed by the low end torque. Have a C6 LS7 car now, and that ones a different story.
Drifting
Joined: Dec 2007
Posts: 1,309
Likes: 24
From: Coastal Georgia
C2 of the Year Finalist - Modified 2020
I'll have less than $5000 in my swap when all is said and done, including the LS1 and T56...
It's also quite easy to put 400rwhp down with an LS motor with simple bolt-ons and a cam swap.
It's also quite easy to put 400rwhp down with an LS motor with simple bolt-ons and a cam swap.
Intermediate
Joined: Feb 2005
Posts: 41
Likes: 0
I'm with "riggs", as one thing changing a SB to an LS, but you're certainly not going to get the 454 torque with a smaller LS, unless you bolt a supercharger on it. If having the 73' BB redone, good opportunity changing some internals, to really get that thing roaring. I had a C5 6 speed LS1 Vette, and can’t say I was really impressed by the low end torque. Have a C6 LS7 car now, and that ones a different story.
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
You can make good torque with an LS. I'm getting 500 at the flywheel with just a head and cam swap. That's more than anyone could need for the street. The other issue with torque is if you can't hook it up, its useless. The 500 mark is just about at the stock C3 rear ends capabilities. In my case, if I want more torque, I'll work on the rear end and possibly do another cam swap. The cam I have is mild for an LS.
Intermediate
Joined: Feb 2005
Posts: 41
Likes: 0
You're certainly not getting any argument from me on LS motors, as on my second one, and love these things. While I believe you're getting 500 ft/lbs on yours with some work, surely it's at a rather high rpm. 454's will pull out tree stumps, barely off idle. Not in love with BB's myself, but if the op already has one, why not work with it.
A lot of LS guys like the l92 heads and they put out tons of power up top, but I wanted something for street use. TSP helped me out picking the right components for my application. In fact one of the guys that. Works there built the same motor. This motor would be happy in a truck as well. It has huge low end torque.
The OP could keep his BB for future use or resale of the car. I did this with my original 327 and Muncie. Big blocks are nice for going straight, but It's like pushing a brick around a corner. I don't mean to offend anyone, but if I can have big block power in a small lighter package, I'm way ahead of the game.