I want a PC now and add NOS this winter. is the PCIIIR or usb better. I can get a new IIIR for 175-200.00 or a usb for 275.00 which is the better one...Thanks Bill

THE PC3R does have the Ignition Module but that is what causes it to have problems! I had to get rid of my PC3r for a PC3 to make sure things did not change! The USB has 250 RPM Sections where the PC3 has 500 RPM Sections. IF you get one and want it for NOS get one that can switch Maps!

The USB is far better,cells every 250 vs 500 rpm on the 3r.
I have the USB,ignition module and map switch,nice setup for spray.

Is it hard to get a map for spray and aftermarket exhaust/filters?

FOr aftermarket no problem! None for Spray and how could they? no one knows how much spray you are going to use and at what altitude and what equipment you have? All I do is tune it on the Dyno and add 20% more fuel when I was running a 60 Shot but now with a 150 shot it is all different because everything is set for the Heavy Spray! There is NO PLUG & PLAY For NOS!