I'm gonna make this short and sweet. I own two fullsize Blazers,an'89 and a'85,what do I have to do to put the T.B.I. engine,tranny and t-case,as well as the '89's power doors and 'gate into/onto the '85? I'm assuming I will need the '89's fuse panel,gas tank and some of the wiring harness,but,I'm not to sure about anything else like gauge cluster and so on.

             thanks for any help.

I see you seem to have the same basic problem as me....no one wants to answer you......i can't give you the basic engine swap and wireing answers...........assuming that both engines are v-8's that should swap with no problem........unless you are good at splicing wires and there will be lots i would just swap out wireing harness........i am not sure what hook ups are on the back of your gauges but i am going to say it is safe to say you will have to swap it out ..........i know there is a difference but measure to see if the whole dash as a whole will fit in there........that way you can keep all the wires that hook up in the steering collum too.......the shaft size should be same and slide up......you will have to check.......also think about the newer seats if you like them......I mostly dragrace and have swapped this before into an older truck and had to keep a lot of the wireing.............so if i had to do it again i would keep the whole harness together.........on gas tank you may be able to keep your old tank only if the drop in fuel pump and sender will line up with the hole in your old tank.......if not just get out the measureing tape......also keep in mind you will need the EFI fuel lines.......

This might not be a lot of help at all, but i know for around $350 you can get a wire harness from Painless Wireing so that you do not have to cut, splice and tape up the other ones.  From what I have read and seen they are supposed to "painless", so all you would need to is keep you computer out of your 89, and it might be easier than trying to figure out what wires you need and what ones you don't.  Me and a friend to the TBI motor of an 89 suburban with the same plan put it in something else.  We attempted to just pull out all the wires we thought we would need till we took the dash apart and found out excatly how many wires there were behinde it.  There is a lot.  I belive the Painless kit would be the way to go.

 And as far as your gas tank goes you might want to look at the putting in an in-line pump.  I know Jegs and Summit sell pumps that create enough PSI to run your motor.