Looking for best bang for my buck on LSx motor

698 Views 21 Replies 9 Participants Last post by Bcm, 9 d ago

Bcm

Discussion Starter · 26 d ago

I have a 97 extended cab, 2 Wheel Dr., 4.3. Automatic.
This will be a driver, not a drag truck. I’m looking at getting a complete motor and transmission from a junkyard and trying to keep it under a $10,000 budget. Which LS motor do I start looking for?

1 - 20 of 22 Posts

bk2life

· #2 · 26 d ago

Bcm said:
I have a 97 extended cab, 2 Wheel Dr., 4.3. Automatic.
This will be a driver, not a drag truck. I’m looking at getting a complete motor and transmission from a junkyard and trying to keep it under a $10,000 budget. Which LS motor do I start looking for?

10k budget is pretty high. If you keep your wits about yourself, you wont spend over 5k.
If you can do the work yourself, and stay away from shiny things that take your money.
where are you located?
4.8/5.3s are roughly $400 in the junkayrds by me, complete, minus AC compressor.
4l60s are about the same, usually cheaper, but, no matter what, tke the 4l60e and have it rebuilt with performance parts. This will set you back around $1500. If you dont, you will break the 4l60. have it built to handle power right from the beginning and have zero issues later.
And what is a driver compared to a drag truck? there are 7 second 1/4 mile street legal drivers out there.
you obvisouly want to race and mess around, otherwise you wouldnt want a V8.
make a list of what you want, and we can help more.

Salty Crusty

· #3 · 26 d ago

5.3L is an amazing engine for being no larger than the old school 327. I have one with over 200K on it, has more power than any 350 I ever owned, knocks down decent mileage and has oil pressure like it was new.
I prefer aluminum block engines for weight savings but they are usually double the price of a comparable iron block engine.

Reactions: 1

Tranzman

· #4 · 26 d ago

I'm using a LM4 short-block that was gutted & swapped to gen 4 rods/pistons & 243 heads from a $100 donar LS4 engine out of an Impala.
I built my own transmission.
4 wheel disc brake conversion (axle and all).
I'm using the Holley Corvette accessory drive kit. I would buy the R-4 kit if I was doing another S10.
It's into me for about 6K plus for the basic swap stuff, I decided to give it a paint job (with my Nephew's help) and that added 1.5K overall.
with some careful planning and trading you may just get by for around 5K. It's always nicer to have XX set aside and come in way under budget.

Reactions: 2

Bcm

Discussion Starter · #5 · 26 d ago

Bcm said:
I have a 97 extended cab, 2 Wheel Dr., 4.3. Automatic.
This will be a driver, not a drag truck. I’m looking at getting a complete motor and transmission from a junkyard and trying to keep it under a $10,000 budget. Which LS motor do I start looking for?
[/QUOTE

bk2life said:
10k budget is pretty high. If you keep your wits about yourself, you wont spend over 5k.
If you can do the work yourself, and stay away from shiny things that take your money.
where are you located?
4.8/5.3s are roughly $400 in the junkayrds by me, complete, minus AC compressor.
4l60s are about the same, usually cheaper, but, no matter what, tke the 4l60e and have it rebuilt with performance parts. This will set you back around $1500. If you dont, you will break the 4l60. have it built to handle power right from the beginning and have zero issues later.
And what is a driver compared to a drag truck? there are 7 second 1/4 mile street legal drivers out there.
you obvisouly want to race and mess around, otherwise you wouldnt want a V8.
make a list of what you want, and we can help more.

I live in Georgia and I’ll be doing all the work myself. When I said about getting the motor from a junkyard, I mean like the motor transmission, wiring, harness computer, Excelerator pedal, ignition, all from the same vehicle. Then I have a wiring harness made to fit my current 97 dash gauges to look like the motor came from the factory in the truck. It’s going to be kind of like a daily driver but I’m retired so I don’t daily drive anywhere, but when I want to go to the grocery store, I want to get there fast. 😁.

Rhotpursuit

· #6 · 26 d ago

Bcm said:
when I want to go to the grocery store, I want to get there fast. 😁.

Careful...you'll scramble your eggs.

Reactions: 1

Bcm

Discussion Starter · #7 · 26 d ago

Tranzman said:
I'm using a LM4 short-block that was gutted & swapped to gen 4 rods/pistons & 243 heads from a $100 donar LS4 engine out of an Impala.
I built my own transmission.
4 wheel disc brake conversion (axle and all).
I'm using the Holley Corvette accessory drive kit. I would buy the R-4 kit if I was doing another S10.
It's into me for about 6K plus for the basic swap stuff, I decided to give it a paint job (with my Nephew's help) and that added 1.5K overall.
with some careful planning and trading you may just get by for around 5K. It's always nicer to have XX set aside and come in way under budget.

I read somewhere else that they recommended LM4 between year 03 and 05 with vin code P because it was all aluminum.
I just got mine back from the paint shop. It was 5k but it is show quality and better looking than my 2020 Chevrolet paint job.
Why do you say you would use the R-4 kit versus Holley Corvette access drive kit?

Racer-X

· #8 · 26 d ago

At your budget, you have a couple of choices.

You could get an older Gen III engine like an iron 5.3 (LM7 or L59) from an older (1999-2007) truck. Use that as the basis for a modified, "hot rodded" engine, and have a really nice 400whp or so. Major mods to build on the engine IMO would be 99mm bore with 99mm pistons (every iron LM7 or L59 block I've ever seen will handle this). Better heads (LS4 was mentioned, and those are plentiful and inexpensive, or go aftermarket), truck intake or TrailBlazerSS intake or aftermarket if you want. I'd also want the Corvette or F body accessory system, to shorten it up at the front to give you more room for radiator and fan, and to at least have a possibility of keeping your air conditioning.

Or you could get a more modern engine (maybe LS2 from a GTO, or LS3 from a Chevy SS 2014-2017, or if you don't mind a 6 speed, from a 2010-2015 Camaro with the manual). Lower mileage, lighter weight aluminum block, and 430 at the crank in stock form, probably pick up a bit from the headers and exhaust. These engines would need less rebuild work, and probably last longer, and probably get better fuel economy.

BTW, I'm in north Georgia if you want to DM for more details.

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Reactions: 2

Tranzman

· #9 · 26 d ago

Bcm said:
I read somewhere else that they recommended LM4 between year 03 and 05 with vin code P because it was all aluminum.
I just got mine back from the paint shop. It was 5k but it is show quality and better looking than my 2020 Chevrolet paint job.
Why do you say you would use the R-4 kit versus Holley Corvette access drive kit?

Because the R-4 kit gives you an additional 1.5 inches of clearance on the passenger side front. It is also approx. 4" shorter than the SD507/SD508 compressor. I'm not 100% sure but I believe that the additional clearance will allow you to run the OEM coolant bottle/PCM mount.

Reactions: 2

Tranzman

· #10 · 26 d ago

Racer-X said:
At your budget, you have a couple of choices.

You could get an older Gen III engine like an iron 5.3 (LM7 or L59) from an older (1999-2007) truck. Use that as the basis for a modified, "hot rodded" engine, and have a really nice 400whp or so. Major mods to build on the engine IMO would be 99mm bore with 99mm pistons (every iron LM7 or L59 block I've ever seen will handle this). Better heads (LS4 was mentioned, and those are plentiful and inexpensive, or go aftermarket), truck intake or TrailBlazerSS intake or aftermarket if you want. I'd also want the Corvette or F body accessory system, to shorten it up at the front to give you more room for radiator and fan, and to at least have a possibility of keeping your air conditioning.

Or you could get a more modern engine (maybe LS2 from a GTO, or LS3 from a Chevy SS 2014-2017, or if you don't mind a 6 speed, from a 2010-2015 Camaro with the manual). Lower mileage, lighter weight aluminum block, and 430 at the crank in stock form, probably pick up a bit from the headers and exhaust. These engines would need less rebuild work, and probably last longer, and probably get better fuel economy.

BTW, I'm in north Georgia if you want to DM for more details.

I'm running the OE V-6 radiator and a Malibu dual fan set, sitting in the OE mount holes. It's all sitting on the Holley mount system and Holley cross-member.
FYI the LM4 is an all aluminum engine It is for the 2003-2005 Trailblazer, Envoy & SSR. It has dished pistons and 706/862 heads. Keep in mind that the block must be drilled for the dipstick tube. It's very simple to do, just want to get it done before you assemble the engine..
Here is a link to all the spec's

www.onallcylinders.com

LM4 5.3L Vortec 5300 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

The LM4 is a 5.3L, Gen. 3 small block engine used in GM trucks between 2003 and 2005. It’s is very similar to the LM7, except that it’s built on an …

www.onallcylinders.com

www.onallcylinders.com

Reactions: 1

oldeerslayer

· #11 · 26 d ago (Edited)

I have the 91 Camaro R4 on mine. The Camaro has a smaller pulley so the compressor turns slower at higher RPMs. It's also tuned to shut off above 5K. I'm running the stock coolant bottle and computer bracket. I was also able to save time and $ by using a stock 94 4.3 dual hose assembly off the compressor to the condenser and accumulator. Had to slightly tweak the aluminum tube part carefully for one side. I did use an original hose assembly from a junkyard. Tried 2 new replacement ones that were "Improved" with thinner wall hoses that kinked.
The stock GM PCM's 0411 and P59's are tuned to shut the compressor off if the engine is spinning above 5250 RPMs.
The PCM will turn also off the compressor when the throttle position goes to 100%.
I believe those are both adjustable with HPT.
The Gen. 3 aluminum block L33 engine came in Chevy and GMC trucks from 2005-07. It was known as the Vortec 5300 HO and made more power than the older LM4. This was due to higher flowing Cathedral port heads, more compression, and a slightly bigger cam. Harder to find, but not impossible. Heads and pistons are already done so no need to tear it down.
I've got an L33 longblock I'd part with, but it's high miles and could use crank turning and bearings. I'd hone it, put in new rings and do the heads. PM me if you're in the midwest and interested.

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Tranzman

· #12 · 26 d ago

Yes the L33 engine carries a casting #12572733 and used gen 4 rods/ flat top pistons (floating) and 243 heads. had a 9.9 compression ratio and 310HP rating.
That's the engine I was told I was buying. Upon delivery is when I found that it was only the LM4, so I got got it cheap...
The LM4 had was a conversion motor 2003-2005, meaning it had gen 3 rods/pistons 2003-2004 & gen 4 rods/pistons for 2005. It also used 1st design cam bearings for 2003, 2nd design for 2004-2005. These fact's led me to believe my engine was a 2004. It had gen 3 rods/pistons (pressed fit) and 2nd design cam bearings. The kickker was it took 1st design head bolts 2003, 2nd design was supposed to used from 2004-2005. It has a 9.5 C/R and the small valve 706/862 head castings that gave it a 290-300HP rating.
The LS4 engine is similar in design to the L33, it's just been shortened on both ends, has the small bell-housing and no provision for a starter (starter mounts to the bell-housing). found that for $100 and used the parts to clone my LM4 to an L33.
Now I realize that I did all that work for 20HP, well that's before the cam swap. My nephew rates it around 400HP now... Whew!!

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2ToeRacing

· #13 · 16 d ago

I'm with ya,I figure about 10K for the swap. I'll be doing all the work all I need now is all the parts. Where are you guys located in Ga? I'm in Duluth.

Bcm

Discussion Starter · #14 · 15 d ago

2ToeRacing said:
I'm with ya,I figure about 10K for the swap. I'll be doing all the work all I need now is all the parts. Where are you guys located in Ga? I'm in Duluth.

I’m not far from you. I’m in flowery branch Ga. Trying to find a motor and transmission wiring harness is not as easy as I thought it would be lots of scams on Facebook marketplace.

remops

· #15 · 14 d ago (Edited)

I used car-part for finding my engine. I just did a quick search with Duluth,GA area code 30096 and used envoy xl 5.3 engine. Several engines these are the LM4 aluminum block 100lbs lighter than cast iron. Also engine came in Buick Rainier, TrailBlazer EXT and Isuzu Ascender . Make sure you get the complete engine with harness and PCM and alternator.

Racer-X

· #16 · 14 d ago

remops said:
Make sure you get the complete engine with harness and PCM and alternator.

If it's "drive by wire" throttle body and you don't plan to change that, you'll need the accelerator pedal assembly as well, and the harness for that.

Reactions: 2

remops

· #17 · 14 d ago

Good point! Along with the wire harness to the pedal and the tac. My envoy wire harness was part of the body wireing and not a straight shot need to splice the wire harness. So get both ends.

Racer-X

· #18 · 14 d ago

2ToeRacing said:
Where are you guys located in Ga? I'm in Duluth.

I'm up 575/515. north of Canton, south of Blue Ridge. I don't like to get too specific because I've had issues with stalkers before. Not from this forum, but still, I use the same basic profile name everywhere.

Racer-X

· #19 · 14 d ago

Also, on the topic of drive by wire throttle, for anything that's not an all out race car, I actually like the drive by wire setup. For these trucks, with so little weight on the rear axle when empty, and so little grip back there, limiting throttle opening in first gear is actually a good thing. Saves wear and tear on the rear leaf springs, too, and cuts way down on wheel hop.

I actually converted a restomod antique back to DBW throttle for those exact reasons. A cable throttle plus a driver that was abusive was wreaking havoc on 75+ year old leaf springs that were designed for 100hp, not 400hp. With DBW and some tuning, we were able to manage in the tune what the driver was unwilling to learn with his own foot.

2ToeRacing

· #20 · 10 d ago

Racer-X said:
I'm up 575/515. north of Canton, south of Blue Ridge. I don't like to get too specific because I've had issues with stalkers before. Not from this forum, but still, I use the same basic profile name everywhere.

WOW, stalkers, now that's crazy, but I understand.

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