I was wondering if their is a difference in the 88 mustang GT pcm and the one that is in a 90 LSC. Could their be any proformance gains by using the 88GT pcm? If any body has an idea please inform me.

I was wondering if their is a difference in the 88 mustang GT pcm and the one that is in a 90 LSC.

Yes.

Could their be any proformance gains by using the 88GT pcm?

No.

I was wondering if their is a difference in the 88 mustang GT pcm and the one that is in a 90 LSC. Could their be any proformance gains by using the 88GT pcm? If any body has an idea please inform me.

You'd have to convert your car to mass air to use that ECM. Won't work if you just plug it in.

The 88 GT is speed density just like the 90 LSC. I think I am going to take a chance and try it to see what happens.

You would notice much more signifigant gains from doing other modifcications such as exhaust, gears, heads, etc. All the work from switching out this computer and still leaving it speed density will probalby little "seat of the pants" improvement if any at all. I wouldnt even bother. Do some upgrades and convert to mass air.

The 88 GT is speed density just like the 90 LSC. I think I am going to take a chance and try it to see what happens.

We're both kind of right. The 88 GT (in California only) was mass air. I couldn't remember what year it was exactly, though.

But yeah, sounds like a waste of time to me, too.

Why would you think there would be a gain in using a computer that is not designed for your application? The Mustang is several hundred pounds lighter and has many other differences that affect driving characteristics, so putting a Mustang computer in a Mark VII would produce no positive results.