Putting an LB7 in an02 2500 Burb

[dmax_ty]

Picking up an 02 burb with the 8.1 and I’m wanting to drop a LB7/Allison into it. Would I need to swap to a 2500/3500 pickup front and rear axle as well?


I’m sticking with the ol pound 7 just for ease of wiring and having everything talk and jive. I’m just trying to compile a list of what’s exactly needed and came to the knowledge center for help.

I’ll get pics posted of the burb and hopefully some along the way.

 

[JoshH]

You don’t have to swap the axles if you don’t want to.

 

[dmax_ty]

Oh really? From what little I’ve read and studied I thought I may need to. Thanks for the heads up. With it being the 3/4 ton already, does it still need a body lift to fit the diesel and Allison?

 

[THEFERMANATOR]

The front axle is the 9.25" as the pickups. 8.1l Burbs got the 10.5" rear axle where the dmax trucks got the 11.5" rear axle, but the 10.5" is plenty strong in my opinion. Mine has held up to all kinds of abuse with no problems. Remember you need an 01-02 lb7 to make the swap easiest. A body lift(or the raked body lift) is a requirement to get the cooling stack to fit in. You will have to do some custom fab work to get the factory dual tank setup to work along with custom tuning.

 

[dmax_ty]

10-4, thanks Ferm. I have been hunting for a 01-02 power train. I’m wondering if the 4.10 gears are a little too short for the 5-speed. Thoughts? Thinking of 3.55s.

 

[darkness]

Depending on what tire size you run, it would probably be cheaper to do a 6 speed conversion. 4.10 gears pair with a 33” tire well. They are actually closer to 34” when comparing speed vs rpm.

 

[dmax_ty]

As soon as typed that out, that same thought came to mind. By the time I recalibrate the speedo for 33ish tires, 4.10s would keep me close to a stock 3.73 geared pickup.

 

[THEFERMANATOR]

I run 3.42's(3.55 is not available, it goes from 3.42 to 3.73) in mine and love them. 4.10's are way to low unless you're running a 34" tall tire or bigger. I remember talking with Eric about his 1st build and it had 4.10's with an lb7, and he said they were low enough to the point it made it not fun to drive out on the hwy.

 

[Chevy1925]

What kind of speed do you normally run down the highway, what’s your daily elevation and do you or will you be towing with it? That would help determine if you really need to re-gear.

Simple option is I’d you have a donor truck, you can swap axles and get 3.73’s without any additional cost for a 6 speed conversion or buying gears.

 

[dmax_ty]

James, I live up in the clouds in Utah. Elevation of 6500+. Some towing, mostly highway driving. My 04 GMC was stock geared on 33’s and did fine. The 07 with the six speed took some tweaking. I adjusted shift points so it wouldn’t shift into 6th until 65 mph. Worked out great as it would lug around 1500ish RPM at 60mph with the speedo adjusted for 33s, it towed MUCH better and was less annoying to drive. It seemed to like running at 63mph while towing (EGTs, ECT, and oil temps were kept in check at that speed as well at/above full GCWR)

I think 3.73s would be the ticket with the 5 speed on 33ish tires.

 

[dmax_ty]

Gonna bump this back up. Finally getting my hands on to the Burb that’s on the slate for the heart transplant. Will post pics STAT.

 

[dmax_ty]

Finally picked it up. I’ll get some more posted up once the weather clears up. It’s pretty rough but hopefully I can get it dialed back in.

 

[KEVINL]

Cool i just swapped my 01 Yukon to a Lb7 let me know if you have any questions