A9L is from an 89-93 Mass Air Mustang. The 86-87 Mustangs were Speed Density systems with no MAF sensor. 88 was a change over year, with CA Mustangs being Mass Air, other states...I'm not sure. Easiest way to tell is look up the ECU code on FFI.com, and see if the harness has the Mass Air Flow plug/pigtail. I think you can convert an earlier harness to work as a Mass Air harness with the addition of a MAF pigtail and a few other changes....what they are, I dont know.