12 Yukon 5.3 need more torque!!

[12Yukon]

So all in all my wife loves it. It is her daily. We have a 26" camper that is 4600lbs fully loaded. And I mean fully loaded. Which never happens cause I don't travel with very much water on it.

I have got the all clear to do a 6.0 or 6.2 swap only because she absolutely will not let me sell this one.

First I want to try a few add-ons because it's really close to where I need it. I can not get it to run in 5th gear with the camper. Running 4th at 3,000rpm is not my cup of tea. I do have the auto Cal and black bear had done an outstanding job so far even with no mods.

So I'm thinking full exhaust and intake at first. All my experience points towards long tube headers. My issue is I can't seem to find a decent system that is not dual all the way. Or is dual with exit on both sides of bumper. Really want to keep it to one side and nothing crazy loud.

Any recommendations for something like this? Also what intake is everyone seeming to go with.

Also if I do end up swapping in a 6.0 or 6.2 aren't the headers all the same?

Thanks for the help. GM for life, but never really dug into our messed with the LS. Old school carbs is all.

 

[avalonandl]

12 Yukon- Your best bet is swap in a 6.2 with AFM delete. The blocks are the same size as the 5.3

Or a 6.0 from a 2500 similar year. They are around.

 

[bfourman]

3k in 4th is likely right in the powerband. Swapping to a 6.0 won’t change that.

What gear ratio do you have? A gear swap will provide more bang for the buck than an engine swap if you’re stuck with 3.42s or similar.

The LS series engines make power higher in the rpm range, which is why tow/haul keeps the rpms higher and in lower gears. You’re not going to lug along at 1500rpm in 5th or 6th towing anything with a LS no matter the engine mods. You would need a diesel to accomplish that. I towed my Jeep to UT and back last fall with my 00 XL 2500; it spent more time at or above 3k rpm than not. Nature of the beast.

 

[12Yukon]

3k in 4th is likely right in the powerband. Swapping to a 6.0 won’t change that.

What gear ratio do you have? A gear swap will provide more bang for the buck than an engine swap if you’re stuck with 3.42s or similar.

The LS series engines make power higher in the rpm range, which is why tow/haul keeps the rpms higher and in lower gears. You’re not going to lug along at 1500rpm in 5th or 6th towing anything with a LS no matter the engine mods. You would need a diesel to accomplish that. I towed my Jeep to UT and back last fall with my 00 XL 2500; it spent more time at or above 3k rpm than not. Nature of the beast.

3k in 4th is likely right in the powerband. Swapping to a 6.0 won’t change that.

What gear ratio do you have? A gear swap will provide more bang for the buck than an engine swap if you’re stuck with 3.42s or similar.

The LS series engines make power higher in the rpm range, which is why tow/haul keeps the rpms higher and in lower gears. You’re not going to lug along at 1500rpm in 5th or 6th towing anything with a LS no matter the engine mods. You would need a diesel to accomplish that. I towed my Jeep to UT and back last fall with my 00 XL 2500; it spent more time at or above 3k rpm than not. Nature of the beast.

5th gear at 75 runs 23-2400. That is where I want it to run. My 03 Sierra would pull anything and hardly ever come out of overdrive. But I had to run 80-85 to keep her at the 23-2400 range. I'm not looking to run 1500. Just looking for a little more lower end torque.

 

[Chrismnj]

Supercharger and BB tune

 

[Kraig]

You’re not going to make a significant increase in torque with intake or headers. Displacement is the answer, just like it was with a carbed engine.

 

[intheburbs]

What axle ratio do you have? Short of forced induction, re-gearing will probably give you the best results.

As an aside, I drove my 2000 Suburban 1500 with 4.10s in 3rd gear all over the country towing trailers, and that put the tach right around 3200.

And my '08 2500 with the 6.0 and 3.73s generally seems happier in 4th when towing heavy. As a general rule of thumb, towing in an overdrive gear should be avoided, as it puts a lot of extra stress on the transmission.

 

[BG1988]

So all in all my wife loves it. It is her daily. We have a 26" camper that is 4600lbs fully loaded. And I mean fully loaded. Which never happens cause I don't travel with very much water on it.

I have got the all clear to do a 6.0 or 6.2 swap only because she absolutely will not let me sell this one.

First I want to try a few add-ons because it's really close to where I need it. I can not get it to run in 5th gear with the camper. Running 4th at 3,000rpm is not my cup of tea. I do have the auto Cal and black bear had done an outstanding job so far even with no mods.

So I'm thinking full exhaust and intake at first. All my experience points towards long tube headers. My issue is I can't seem to find a decent system that is not dual all the way. Or is dual with exit on both sides of bumper. Really want to keep it to one side and nothing crazy loud.

Any recommendations for something like this? Also what intake is everyone seeming to go with.

Also if I do end up swapping in a 6.0 or 6.2 aren't the headers all the same?

Thanks for the help. GM for life, but never really dug into our messed with the LS. Old school carbs is all.

if your engine is flex fuel rated. you can get extra power running E30 or E85

 

[FrankU]

Supercharger and BB tune

This PLUS a big transmission cooler. 4600 lbs isn't that much of a load IMO.

 

[thompsoj22]

Just a thought. find the used denali xl 6.2 that you would like to have at a dealer and let your wife test drive it. chances are she will be all smiles. I speak from exp, we traded our tahoe in for the exact same challenges you are faced with. I did install a 373 in our 03 tahoe and it made a slight difference but not enough to take the "white knuckle" effect out of towing at 3k to 3.5k rpm. The 6.2 tows our 22 ft aljo beautifully and the longer wheelbase keeps me from death gripping the steering wheel while passing big rigs! It may be time to step up to the bigger vehicle?