Streetrod19772000

I have completed the entire swap but I am now into the wiring of this beast. I am having trouble with the dash harness plugs in the 1988. They do not match what I am seeing in other Threads. There are three plugs. I matches and I have all the wires labeled. The other two do not match anything I have found. I also need to pinout the II1, II2, and II3 in the 1999 harness. I have a complete wiring schematic book on the 99 but does not show these three plugs and what wires correspond with numbers on plug. Any help from anyone would be greatly appreciated. I am swapping both the 3.4 and auto trans with transfer case. I swapped the front diff out of the 99 into the 88 also.