alldata is cool...
it should work
always go newer ecu vs. newer harness
as they do alot of software and harware config updates on a random basis.
I am thinking I bought a performance pcm for my 95 dodge
and whoever programmed it did not update the prom.
when I said just chop some g wires and make it work.... I guess Im stuck in the 80s too... and I was thinking about older stuff which is still an easy out option if you ask me.
If you already got the block in, I would cross reference the year make block with the year make harness/ecm and see how many years and vehicles they used that harness/ecm on and what the difference is between it and the previous version - and the latter. it may also be possible to use even newer parts, you never know with these lazy manafacturers. newer harness and ecm may give you more upgrading options if your looking for speed.
I dont know much about the chevy's except I love 'em. but for instance - on my dodge they used the same harness I have from 94 to 96 or so for most dodge rams dakotas and jeep wagons. you will wind up with unused connectors but its way less expensive to make.
by switches I was referring to 4 wd electric lock outs, OD bypass, hi beams and all the like. the harness has to have all the same circuits to work.
yes you can cross-ref by part number thats probably the best waY. It will be alot of research, but its possible.
Is your truck 4wd? considered forced induction?
you know if it turns out to be a hassle you can always put the 2.8 on a skateboard!