wiring harness differences between 88 89 and 90 RRC

[rezdiver]

how much of a difference is there between an 1989 wiring harness( no ABS) and a 90 wiring harness. just from looking at them they look similar, but the fuse box is much bigger on the 1990.

basically i have a 90 solid bare shell and chassis with a semiintact harness( nothing has been cut, but all relays are removed and everything is just hanging there.) and i have a 1989 with a good engine but rusty body. so i want to take the whole interior and engine from the 89 and put it in the 90. the 89 has a production stamp of 1988 december. not sure if there is a difference.
the 90 had ABS so i will take the whole brake system from the 89 non ABS for use.

i also noticed the 89 has a speedo cable, did the 90 have cable or was it electric?

let me know if you have done this or if you have any pointers. I am not worried about power locks and windows, etc. just the main engine, heater, dash switches, and column switches, all the necessary parts