Ls swap (swindle)

[ztk123]

A few months started my 1st ls swap. Bought a 52,000 mile 5.3/4l60 pullout to put in my factory 71 2wd blazer. Bought a custom harness sent off the PCM for flashing and tuning. Followed a lot the awesome threads closely on the fuel system and other install info. Anyway, got everything ready to run and when I plugged in the code reader to scan for codes, up comes the vin # and at that point. I discovered to my surprise I had a shiny 4.8 in the engine bay! Needless to say I was MAD! Looks like I'm not the first one to fall victim to this kinda thing. I called the guy up that I bought it from and he claims he is as surprised as me??? He said he will make it right (for whatever that's worth). Now I'm trying to decide if I should keep it or start over. The cam I installed raises the HP by about 45 and the torque by about 30 according to the graphs. I also installed headers, electric fans and a street & performance CAI intake system The blazer weighs about 3500lbs (a little less without the top and 4 wheel disc brake upgrades and minus old engine and trans). and the sierra the engine came out of ways about 4400lbs. I started out just wanting a good a cruiser and felt the 5.3 was a good choice. Just looking for thoughts and advice as well as vent a little. Might make someone a good deal on a 5.3 lookalike! Lol
Thanks,
Mike

[ls1nova71]

I had almost the same.thing happen to me, only I pulled it! It was in a 2002 Tahoe 2wd. I didnt think they put 4.8s in them, found out otherwise when HPTuners was plugged into it to get rid of VATS. Depends on how the guy is going to make it right, but I would probably just keep it since youve done some work to it and were wanting a nice cruiser, it should be more than adequate for that.

Now ill be the first to ask. Where's the pics?!

[ztk123]

I should have proof read my post before submitting! Please excuse my grammatical mistakes and sloppiness. Thanks for the reply ls1nova 71. Here is the link on my build thread last year. I will post some engine pics soon.
Thanks again,
Mike

http://67-72chevytrucks.com/vboard/s....php?p=6826510

[LSV8]

This is a very common occurrence with our customers. When the 4.8 and the 5.3 engines are removed from the trucks, they are almost impossible to differentiate. There is a way however, Remove a spark plug and either with a borescope or a feeler... All 5.3 truck engines have dished pistons. All 4.8L truck engines have flat top pistons. No exceptions from the factory. They use the same heads. So the combustion chambers being the same with the 4.8's shorter stroke; the CR's are nearly identical. We have customers making great power with both engine combos.

[LSV8]

Another nearly identical scenario is the difference between the iron block 6.0L's that the salvage yards want big bucks for. The most common is the LQ4 (dished pistons) and they tell people that it is the higher output LQ9 (flat tops). There again, there is no other reliable way to differentiate them other than peeking at a piston. Hopefully this will help someone.

[BR3W CITY]

5.3-4.8=.5

5.3/.5= 10.6


So you got about 94% of what you paid for.
When you put it like that, it doesn't seem all that bad.
Just ask for 30% of your cash back, and you'll still be over 20% ahead.

[kevmac]

Originally Posted by BR3W CITY

5.3-4.8=.5

5.3/.5= 10.6


So you got about 90% of what you paid for.
When you put it like that, it doesn't seem all that bad.
Just ask for 30% of your cash back, and you'll still be 20% ahead.

Nobody ever said anything about math being a requirement on this board, great idea though!

[BR3W CITY]

I can go further;
Assuming its a GenIII, and a common one (non aluminum block), and excluding the outlying 99-00 early models, the 4.8 made anywhere from 270-285hp.
270+285/2= 277.5 avg hp

The same qualifiers for the 5.3 are from 285-295hp
285+295/2=290 avg hp

290-277.5=12.5hp difference.
12.5/290= 4% difference

290hp avg / 5.3L = 54.71hp/L
277.5 avg / 4.8 =57.8 hp/L

Assuming the engine cost a round # like $1k;
1000/290= $3.50/hp
1000/277.5=$3.60/hp
If you can get that 30% cost back $3.60*.30=1.8 , $3.60-1.8=$2.52/hp

$3.50-2.52=.98 difference cost per hp. 2.8% difference in cost per hp



I got lost somewhere in all that....but I'm pretty sure the math is right. I think.

[ztk123]

Thanks for the replies guys! I have learned a lot of lessons about this and LS engines. BR3W CITY you are blowing me away with the application of logic with the calculations! It's pretty awesome and makes sense. It is a Gen III 2005 from a sierra. I'm thinking with the cam swap and a few other upgrades it's probably in the 325hp range. Considering these trucks had such low hp from the factory I should be satisfied with it.

Thanks again,
Mike

[BR3W CITY]

Ya I wish my damn Algebra teacher could see me now...but he's in jail for embezzeling 1.2million from my school...no joke.

[old bastard 67]

^^ lol

[crazy longhorn]

Originally Posted by BR3W CITY

Ya I wish my damn Algebra teacher could see me now...but he's in jail for embezzeling 1.2million from my school...no joke.

My English teacher, got busted for being involved with a "chop shop"! Damn, you just don't drive a Stuts to school, & claim that you had a good inheritance The good life is so good....till your are busted? last time I saw him yrs later, he was a cashier, @ a 7-11 (ouch)? Longhorn

[cableguy0]

This article will make you feel more comfortable. http://www.hotrod.com/techarticles/h...g_bang_theory/

[crazy longhorn]

So that you know, the 4.8/5.3 blocks are the same....the paint dot will be on either one, if you can still see it! The block, will be 4.8, or 5.3 Look....which side the paint stamp is on?@ the vin code....The heads on my 5.3, were stamped 4.8....as said, the same castings, on both....mine had dished pistons, & a 3 5/8" stroke(5.3)

[Clyde65]

I say run the 4.8, you have put some $ in it and it will do just great at your intended use. It will also get you good mileage too!

[Hart_Rod]

The 4.8's really like boost, so I say throw a turbo on it with the money you get back from the seller. OBTW, this would throw all of your math out the window BR3W.................

[BR3W CITY]

Don't make me get out the Ti-92....I will start doing thermodynamic and VE calc's (really really BADLY).

And it wouldn't COMPLETELY screw my math up. The HP/L calcs would still be the same to start. If you ballparked a turbo, you can get the chart for flow@boost and make some estimates.

There is a way to extrapolate boost #'s and say it "moves as much air as X size engine", if you use generalized #'s....but I don't have a clue how to calc that.

[slowcpe]

I like Hart Rod's logic: get some money back and throw some boost at it

[Clyde65]

Originally Posted by BR3W CITY

Don't make me get out the Ti-92....I will start doing thermodynamic and VE calc's (really really BADLY).

And it wouldn't COMPLETELY screw my math up. The HP/L calcs would still be the same to start. If you ballparked a turbo, you can get the chart for flow@boost and make some estimates.

There is a way to extrapolate boost #'s and say it "moves as much air as X size engine", if you use generalized #'s....but I don't have a clue how to calc that.

Sounds like fuzzy math to me!

[BR3W CITY]

Originally Posted by Clyde65

Sounds like fuzzy math to me!

Everything I do seems a little fuzzy.

[68basket]

Hey, sorry i didnt get back to you when you sent that pm. Hope you got the tac problem worked out.

I think you should take out the whole combo, sell it to me then go buy a 6.0!

Taylor

[solidaxel]

Run what you have now, you will be so shocked how much better the low end is and up to the top of second gear, you will be very happy with what you have!

[e015475]

I thought this was pretty common knowledge, but I'll repeat this at the risk of telling somebody what they already know.

There is a 9 digit VIN stamped or laser etched into the LS block.

Unless the motor has been decked, you'll find it on a tab that sticks out from the block deck at the back of the left cylinder bank. Usually it is peened into the block with a series of dots to form numbers/letters, but I've also seen them marked with what looked like a vibra-peen marker by hand.

On aluminum LS motors, you can almost always read it, but for iron blocks, it is frequently rusted over. On an iron block you can read it if you'll sand it with some wet-or-dry sandpaper with a little WD-40 as a lubricant. Holding a flashlight at an angle to the pad where the VIN is stamped is sometimes helpful in reading the letters.

For a LM7 5.3, the 8th position in the VIN will be a "T". but for a 4.8L it will be a "V"

Knowing the motor's 9 digit VIN, you can take it to a dealer and find out what vehicle it came from. Mine drove me nuts looking for O2 sensors that fit the harness connectors until I figured out my motor came from a van, and they took a different sensor.

[BR3W CITY]

There is a Vin stamping but I don't believe its the full VIN, its a 9 digit partial, or if you got a non-truck LS, its actually a serial # that does not translate directly to a vehicle ID unless you give the serial to a (helpful)dealer. Full VIN's are 17 digits.

Its also damn near impossible to get at to read, especially with the engine installed...and some dealers really dance around the "giving out free information" thing these days.

[e015475]

Correct - the VIN on the motor is only 9 digits and not the complete VIN number, but you only need to read the 8th to get the displacement/type.

The WD40, sandpaper and flashlight trick has worked pretty well for me, but most of the motors I've bought were from Arizona where things don't get super rusty.

If you're at a junkyard/CL looking at a motor in the car/truck, you can always read the VIN under the windshield glass and see what the 8th digit says before they pull it, and look at the block VIN before you haul it home.