The engines in 88 were stock Ford. The suspension was intensely upgraded with springs, struts, shocks, bushings and more. The interior got completely redone on most cars with Flofit seats and matching door panels, a Momo steering wheel and a different shift knob. It also got a Hurst shifter.
Saleen ground effects won't fit on a GT. 99.9% of Fox body Saleens were built on LX cars. The front and rear pieces are attached to the stock LX bumpers and won't work on a GT. If you were to change your bumpers to LX, your body side mouldings would no longer line up with the bumper covers and you'd have to change your tail pipes as well.