LB7 Swap

[jstolk2]

I apologize ahead of time for anything dumb I might say or do. I'm a complete noob. With that said:
Its time to resurrect my 1983 K20. It was my first truck. Bought it when I was 15(I'm now 30). I've already got all new body panels for it. I was just going to freshen up the 355 that's in it and call it good. But the other day a friend of mine made me an offer I couldn't refuse. He sold me his wrecked (cab damage) 2003 2500HD Duramax ECSB. Truck has just over 100k miles. And the Allison only has 5k miles on the rebuild. So now I'm quickly developing a new plan! I've seen amazing LB7 swaps online and on this site. I doubt my project will ever hold a candle to the ones I've seen on here. But I ultimately just want it to be reliable, and just a decent looking usable truck. Initial plan is use the LB7, Allison, Tcase, and rearend from the 03, and get a Ford axle to run up front. I'm obviously just starting the planning stages and I'm trying to gather all the information I can. My initial thoughts are to take my K20 down to the frame, blast it, and box in the whole frame so that I can actually utilize all the pulling power the LB7 has to offer. Would this be a good first step?
Any wisdom, thoughts, or foresight would be greatly appreciated.

 

[marks86]

First off it might be easier to run a np205 out of a k30 then it would to install a drivers side drop axle and hook up an 03 transfercase.

So that being said Id put a k30 drivetrain in the truck as a starting point. When the frame is all ready to go, your going to have to research a few main things.

1. Engine Crossmember/Motor Mounts-look for a company that makes them unless your good with a welder, It might be easier to buy a premade one

2. What your going to do for wiring? the stock 03 Harness or you can buy stand alone units for the LB7 and the Allison

 

[jstolk2]

Thanks for the input Mark. I'll write down your considerations in my notes.

I'm a decent welder, but by no means an expert. My brother on the other hand is a welder by trade and also an instructor. So luckily I have him to call over when I need a hand. But I still like the idea of finding premade mounts.

For now, I was just figuring on utilizing the factory 03 harness. I'm not sure how many convenience features I'll want to pull from the 03, but I figured the wiring would already be there then for those features if I choose.

 

[marks86]

Thanks for the input Mark. I'll write down your considerations in my notes.

I'm a decent welder, but by no means an expert. My brother on the other hand is a welder by trade and also an instructor. So luckily I have him to call over when I need a hand. But I still like the idea of finding premade mounts.

For now, I was just figuring on utilizing the factory 03 harness. I'm not sure how many convenience features I'll want to pull from the 03, but I figured the wiring would already be there then for those features if I choose.

by using the 03 harness, I would use the factory 03 gauge cluster as well

 

[jstolk2]

Yeah, I saw a swap done by someone named Lance. And he molded the new style cluster into his old style dash. It looked awesome.

 

[84 Diesel]

How's the swap coming along? I have 84 k2500 suburban with the 6.2 n/a diesel and I want to do the duramax swap on it.

 

[jstolk2]

Slow. I'm still tearing down the donor truck. I've decided that I'm going to shorten the 03 frame and put my 83 body on it. I've just got too many irons on the fire right now to spend much time with it unfortunately.

 

[87silveradok20]

Chase carrol has a k5 with a duramax swap on Instagram if you are on there his user name is durachase1

 

[Randall12v]

There's a few places you can get aftermarket wiring harnesses for lb7. PPE, BTDieselWorks, etc. they can also modify factory harness for what all you'll need.