You can but your leaving some power on the table for more cost
CK5
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Engine Replacement Advice Request
- Thread starter colbystephens
- Start date
tbi = no like anything other than stock or what the chip is programed for . so if you change stuff it will not run at its best or good until you get a chip burnt for it .
L31 swap for me was not bad at all i had about all the hard parts .
flexplate for 1-peice rear main seal
intake for your fuel needs carb or efi ( more later )
old water pumps fit up as do the drive brackets v-belt and or serp belt . i have 90-95 aluminum serp belt stuff no problem bolting up .
no fuel pump boss but if efi who needs one .
make sure dist has a melonized gear for the roller cam .
i did a holley sniper efi carb replacement unit and it was 500 miles and 3 months of hell . long story ........ get a drink and sit and read
next i went edelbrock pro flo 4 FULL sequential port fuel injection manifold up . WAY BETTER . been working great since then . just upgrade your efi lines for the 55-60 psi pressure and swap on a higher psi pump in the stock sender and run it. i did a ep381 acdelco unit just fine on pressure and has yet to run out of fuel for the L31 needs .
ck5 pfo flo 4 thread
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L31 swap for me was not bad at all i had about all the hard parts .
flexplate for 1-peice rear main seal
intake for your fuel needs carb or efi ( more later )
old water pumps fit up as do the drive brackets v-belt and or serp belt . i have 90-95 aluminum serp belt stuff no problem bolting up .
no fuel pump boss but if efi who needs one .
make sure dist has a melonized gear for the roller cam .
i did a holley sniper efi carb replacement unit and it was 500 miles and 3 months of hell . long story ........ get a drink and sit and read
next i went edelbrock pro flo 4 FULL sequential port fuel injection manifold up . WAY BETTER . been working great since then . just upgrade your efi lines for the 55-60 psi pressure and swap on a higher psi pump in the stock sender and run it. i did a ep381 acdelco unit just fine on pressure and has yet to run out of fuel for the L31 needs .
ck5 pfo flo 4 thread
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Haha! Sounds cool.
I'm going to stick with the super easy stock 5.7L replacement. Then I'm going to wheelin!
I'm going to stick with the super easy stock 5.7L replacement. Then I'm going to wheelin!
beags86
Eastbound and Down
Why not have a local machine shop do a basic rebuild of your current engine?
I did one a few years ago for a plow truck. Just a stock 5.7 tbi rebuild. Got an RV cam. Which does work with the stock ecu. .30 over in the holes
Cost me like 800 bucks. Probably be around 1k now.
bigred88
1/2 ton status
2nd this from personal experience. I was poor and in college at the time. Engine lasted maybe 20,000 miles before I started getting lots of silver in the oil...
It's got a cracked cylinder. Wouldn't that be a non-starter? If not, I should really consider that.
To be honest, another reason I'm nervous about that is because I got so burned by the manufacturer that I feel no confidence about any part of this engine. It may not make financial sense, but this engine makes me sick and it's hard for me to stomach keeping this thing.
beags86
Eastbound and Down
Understand. But a solid builder would put you at ease. As for a cracked cylinder. They sleeve stuff all the time. So it's fixable. But honestly if you have the cash just buy the GM crate. Don't mess around with an aftermarket builder if you feel that way.
It sounds like you already know what you want. Be true to yourself.
Had a terrible phone at the time, but pics of my L31 from the crate through various designs, plus some of the takeout engine. Sounds like you have your mind made up, which is perfectly acceptable...as I'm running a one-off setup anyway, L31 crate made sense for me. But as a swap with TBI, it makes less sense IMO, if you don't need the power.
https://ck5.com/forums/media/albums/l31-crate.1381/
FWIW, while numbers that vary can be found, the L31 at 250HP/330ft-lbs and the L05 at 200/300. Cams specs I can find are L31 .414/.429" Dur. @ 0.050" 191°/196°, and L05 .382/402" Dur. @.050-165.9/174.8
With the Vortec heads claimed/dynoed at 25HP over previous heads, and cam being worth some more power, personally I don't think the induction method has significant bearing on the output. Vortec heads, roller/more aggressive cam are worth 50HP between those two engines. I also think the cam specs and power output differences are such that anyone that tries running an L31/TBI, without tuning, has to be hitting the knock sensor, and probably fairly often, whether they know it or not.
https://ck5.com/forums/media/albums/l31-crate.1381/
FWIW, while numbers that vary can be found, the L31 at 250HP/330ft-lbs and the L05 at 200/300. Cams specs I can find are L31 .414/.429" Dur. @ 0.050" 191°/196°, and L05 .382/402" Dur. @.050-165.9/174.8
With the Vortec heads claimed/dynoed at 25HP over previous heads, and cam being worth some more power, personally I don't think the induction method has significant bearing on the output. Vortec heads, roller/more aggressive cam are worth 50HP between those two engines. I also think the cam specs and power output differences are such that anyone that tries running an L31/TBI, without tuning, has to be hitting the knock sensor, and probably fairly often, whether they know it or not.
I visited my favorite machinist this morning. He thinks it's best if I just buy a new engine. He thinks cost won't be much cheaper for him to rebuild, and so the value between them isn't comparable.
beags86
Eastbound and Down
Never hurts to ask.
79rustyk10
3/4 ton status
Is passing emissions an issue where you're at currently?
I suppose so if he's in the Portland area
Yes.
Hard to beat an L31. My old 98 Tahoe had one, even with 258K ran pretty good, decent mileage, and would shit n git if you put your foot into it. Tranny didn't like it lol, but it surprised me when I would step on it. 3.42 highway gears and 235/85s lol...
79rustyk10
3/4 ton status
I like the L31 idea, but with emissions, I'd keep everything as stock as possible.
Doesn't the GMPP vortec/TBI intake require a whole different EGR system due to vortec heads not having exhaust crossover?
For any future person looking at this, I've found the engine for $2200 here: https://www.newgmengines.com/shop/product/12568758-gm-5-7-liter-replaced-by-12681430/4
I'm thinking I'll see if Summit will price match it, and maybe still do their current $150 off of $2K+ purchase.
I'm thinking I'll see if Summit will price match it, and maybe still do their current $150 off of $2K+ purchase.
I don't know about Oregon but in California you can put newer, but not older
RubberFloorMat
1/2 ton status
Fwiw.
I have a L31 Crate engine in my 75, it was installed by the previous owner and it’s running a carb. Other than stainless longtubes, aluminum vortec intake and a mild off the shelf comp roller cam. It’s totally stock. You can barely hear the cam, it’s has a ton of torque and everyone who has driven or ridden in it says it’s very torquey and smooth coupled with the SM465.
I’m a huge believer in the GM vortec heads as an upgrade to any sbc.
I have a L31 Crate engine in my 75, it was installed by the previous owner and it’s running a carb. Other than stainless longtubes, aluminum vortec intake and a mild off the shelf comp roller cam. It’s totally stock. You can barely hear the cam, it’s has a ton of torque and everyone who has driven or ridden in it says it’s very torquey and smooth coupled with the SM465.
I’m a huge believer in the GM vortec heads as an upgrade to any sbc.
I'm swapping in a stock TBI GM crate motor in a 90 suburban right now. If I remember correctly it's an L44 bought it off ebay from Radley Chevrolet in Va was the cheapest I found at the time in January, I'd have to go look but i think it was $1700 and a $100 visa gift card came with it.
L31 was an emission compliant replacement. I bought one in 05, still sitting in the garage. Wanna put a cam in it before I install it. I have to pull it apart anyway as it's been sitting so damn long. Need to make sure the ex didn't drop a handful of hardware in it!
