I currently have a 1993 Ford F150 regular cab pickup. I'm upgrading the system in it. I already have as follows: Alpine CDA-117 head unit, Polk DXI650 door speakers, Polk DXI570 rear speakers, a Kicker ZX750.1 amp, and 2 Kicker CVT104 shallow mount subs. The amp and subs are part of my current...