What is the difference between the two under hood harnesses? I did a search and could not find anything. This is what I have Thanks

 

The main differences are the MAF burnoff sensor for the 85's and the relays used on the 86-89 stuff. Also, there is a difference in the "pinouts" on the computers. If you want to swap to an 86-89 computer, which I highly reccomend if you are using the earlier stuff, you will have to "re-pin" your connectors.

They have changed things around here and I finally found the link for information you will need....

General Technical FAQ's & Articles

Go to this link and search through all the useful stuff it may tell you what you want to know (besides what you have) and give you options to do a lot more.....

 

I think one of the things I noticed was that the 85 harness plugs at the ecm has 3 connectors. and the 86-89 has 2.