I have a 2011 Express 4500 that had a "small" fire. I got a new harness, intake and ABS module from a 2012 3500. My problem is my ABS modules are different. I am "guessing" it is because the donor truck had drum rear brakes and mine has disk. My question if I get the correct module am I going to be able to repin my 2012 harness to work?

Save yourself and ours the headache and just get the correct module.

You will probably have to have the donor module programmed to the chassis at the dealer.

When repinning stuff, all bets are off.

Are you good at such things?

Do you have diagrams of pinouts of modules and harnesses?

Are you good with a soldering iron and shrink tube?

After some more research it looks like one had traction control and the other didn't.( forgot rpo) One has two rear speed sensors the other only has one. I did automotive electrical for 45 years and fire trucks for 14 so yes I know my way around a pair of crimpers.

. . . and a soldering iron etc.?

Do you have diagrams?

Not yet but I have some time before I get to that point.

Blegh!

Yeah you do!

You'll probably have to cut that intake off of it.

Small fire. OK. You're gonna want diagrams.