no it wont be plug&play.....
1990 will have 2 plugs that connect to the dash harness
1992 will have 1 plug,and depending on whether its early 1992 or late 1992,it may or may not have the fuel pump relays on the harness..in mid 1992-1993 ford moved the FP relays under the MAF instead of under the drivers seat like all the other years
if you have a 1990 dash harness,you need a 1990 engine/computer harness..its an oddball year
breakdown of compatible years:
1987 Notchback - N/A stock 302, TFS heads, Holley Systemax, FTI cam, Astro A5
Best so far: 10.92 @ 123mph with a 1.49 60ft