Does anyone know can I change out my blue/green wiring harness on my 2003 chevy express van 5.3 motor it's awd and cable driven and use a 5.3 pickup harness blue/green cable driven

 

So you want to physically change it on the van? The truck harness is not laid out the same. The length is different, and on the truck it goes into the fuse block, on the van it's different. It's been awhile since I pulled one out of a van, so I can't recall off the top of my head. If you explain a little more clearly the end game, may have more to offer, IDK.

 

Yes I took a van frame shortened put a 1964 ford on it but the wiring is to long and thought if a truck wiring is the same setup but shorter it would be perfect

 

Well in a swap you can use pretty much any harness you want as long as it matches your engine and accessories like throttle body and such.

 

So would it be smarter to buy a whole truck so I have everything for wiring or will just buying the engine wiring work in the same year.

 

I would just buy the engine harness and mod that to work, then buy an aftermarket kit to wire the rest of the truck, headlights, turn signals,wipers,ect. Trying to use all that out of a donor is a lot more work and won't be nearly as clean as just using a kit.