LS swap

[Tommyups]

I have a 67 short bed, interested in doing an 5.3 LS swap.
What’s the ideal year I’m looking for.
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[mongocanfly]

Personally I prefer to look for the earlier ones.. just try to avoid dod and afm..
If you get a dbw, make sure you get all the pedal assembly and tac..

[Tommyups]

Yes, I do understand to stay away from the afm motors.
I do want the 4.8 or the 5.3 so I’m pretty sure that comes out of a half ton,
What I’m asking is what specific years and vehicles am I looking for?

[mongocanfly]

They started with the 5.3 in 99.. 1/2 and 3/4t trucks or Tahoe's are the best place to look.. my LQ9 came from a Escalade.. it was dbw and I changed it to dbc..

[Accelo]

Very difficult to tell the 4.8L from the 5.3's with out looking at the pistons.
The 8th digit on the vin will identify the motor if it's still in the vehicle.

Get the complete package, even a complete wrecked truck if you can.
That way everything fits. It will save you hours and $.

Many of the issues I had can be tracked directly to miss-matched parts.
Most the time they eventually fit.
My transmission as an example.
It was one year off and would bolt to the motor. However it required a different flex plate. So I purchased one and modified it and afterwards figured out it was the wrong flex plate offset. So back to the parts store for another. Easy to double your costs with mistakes like that.

Use a truck motor with the fan mounted on the water pump. Will save a lot of money and wiring hassles if you do.

Drive by wire can be easily converted to drive by cable. But there again you are changing stuff. Easy enough to just get the style you want and stay with it.
As a side note adding cruse is easy with drive by wire.

I also recommend purchasing the complete ECM and harness. One can modify the harness your self. Leave that for your second transplant. You will have enough issues.

[Tommyups]

Thanks for all the input guys. Here’s my truck, it’s got the 292 four-speed in it right now. Definitely going to avoid that AFM, what year was that introduce?

[mongocanfly]

07 for afm (edit)....
thats a sweet truck!!
i would love to have a 292/4spd...always wanted one...never could find one back in the day

[Thealien]

I had a 2005 and it did not have it. I believe 2007 was the first year for AFM

[AussieinNC]

AFM came in when the body changed in 2007....on 5.3 and 6.0.....

From memory anywho...

[Jason Banks]

I'd go 99 to 05. 2003 you could start getting Drive By Wire throttle bodies. Earlier than that were Drive By Cable throttle bodies where you have a cable from your gas pedal to the throttle body, which means you can use your stock gas pedal. Some vans up to about 2006 have the drive by cable throttle bodies also. You could also swap the drive by cable components onto a later engine and tune accordingly.

You are really best getting a whole donor vehicle if you can find one. Or get a complete set up from a junkyard. Engine, intake, fuel rails, injectors, harness, transmission, transmission yoke, engine computer, and if drive by wire, probably TAC module and harness and electronic gas pedal.

If you want cruise control, its probably easier with drive by wire, for the drive by cable you will need the external cruise box from underhood and the associated wiring.

[Tommyups]

I really appreciate all the information. I saw a 2001 truck with 140,000 miles on it for 2K which might be a possibility, it’s a little far away though.

[kev2809]

definitely stay away from that AFM crap. they were 2007-2013 body style. 99-06 had the best truck motors imo. dbc seems easier from what i hear but i went with a 2002 tahoe 5.3/4l60e dbw. i bought the whole damn truck wrecked so i grabbed the motor, trans, engine harness, gas pedal, gas pedal harness, and the box on the firewall for the gas pedal. if possible snag a whole truck. dbc you wont need anything of the gas pedal stuff


oh, and thats a nice truck!

[Thealien]

Cruise is easier on DBW if you are interested in that.

[bigmoe]

I wouldn't walk away from the Gen IV motors with afm. The Gen IV's had a lot of improvements over the Gen III including more stock horsepower. There's a lot of them out there working well. I got a good deal on a low mileage Gen IV 5.3L so I'm not worried about the AFM. I just deleted it in the tune.
If it's a concern you can always do a delete kit with a performance cam. A stage one kit can add 68HP.

[kev2809]

good point bigmoe.

you got yours with low mileage, sometimes when they have high mileage a tune out of the AFM sometimes won't work, (from what I hear anyways) you have to pull the lifters and sometimes cam. when I had my 2008 it had 120k miles but never tried to tune it, it had other issues as well so I sold it. but I have 2 friends that have a 2008 and the other a 2010...both, suburbans and had no issues, even now.

plenty of people do swap these engines, I've just had bad luck on the one I had versus the 2 daily driven 2002s I still own.

[biketopia]

I also would not discriminate a DOD motor. Odd's are you'll open it up anyways, so why not throw a small cam in it and change the lifters and be done with it. Turning it off in the tune isn't a permanent solution, the lifters fail and don't pump up giving a dead cylinder. Lots of times it happens while DOD is active and it just doesn't fix it's self but it happens in 8 cylinder mode too, just poor design.

[kev2809]

good point. if you find one in good condition, snag it. just plan on a cam and lifter swap

[bigmoe]

A few more small advantages to Gen IV I recall.

Their PCM/TCM is smaller which can make for a neater appearance under the hood or not needing as much space if mounting somewhere in the interior.

The brake light connection to the pcm is simpler, not requiring a special brake light switch, just connect the wire to the hot side of your existing switch.

Fuel line routing is simpler because they don't require a return line.

I also discovered that if you're using a Dakota Digital gauge kit plugged into the OBD port the Gen IV will give more info like oil pressure and gear position.

[Jason Banks]

Discoving GEN III didn't have oil pressure in the PCM was shocking. I guess GM routing it through the BCM in the factory installations was good enough. But, for a swap it could be better.

I have Dakota Digital and the OBD BIM, but had to use the separate sensor for Oil Pressure.

[LS short box]

I've done a couple of Gen IV 6.2 swaps. 2010 and 2012 engines. Both had VVT. Neither had DOD. I replaced the the stock cams with three bolt 225I/230E, .600 lift, 114 CL cams. New push rods and springs. Both ran great after a tune.
I converted both to LS3 specs with an LS3 intake and injectors. I used C5 FFR on all my LS swaps.
I'm currently thinking about a new LS engine project. 2000 ish 6.0 liter stroked to 408. L92 heads. LS3 intake and injectors.

[Tommyups]

What’s the best way to go about air conditioning on these LS swaps?
Is it better to use existing AC on the donor truck or something like vintage air?

[Jason Banks]

Yes, you want vintage air. Not sure how the donor parts would fit well.

The beauty of the vintage air kit is, you get an entirely new system without having to piece anything together and it just works.