It won't make as much of a difference with your 92'. The 86' was a speed density engine with pretty rigid spark & fuel maps and it doesn't adapt very well to large changes in engine airflow. Yours is a Mass Air engine and is much more flexible. The changes you've made have already netted you most of the additional horsepower that's available. While I'm certainly no expert I don't think the Mustang PCM will gain you much, if anything. That one's going to be setup to maximize high end horsepower rather than low end torque. You'd probably be better off looking into a chip for yours, that way you can have the computer taking advantage of the changes you've made & putting the HP & torque where you want & can use them most.