Draglites on Cobra with Gt Brakes

Ive bought 99+ PBR GT brakes for the front and gt brakes for the rear of my 97 Cobra, so I could run draglites. Im wanting a 15 x 8 rear wheel and a 15 x 3.5 front wheel. do i need a spacer on the front? Also what back spacing will i need on the rear? Basically i just need what ever information i will need to order the correct wheels for my setup.

Thanks

I allready have the gt brakes for the front and rear. Im putting the cobra brakes on a 4cyl fox coupe that i am putting a turbo coupe motor in to auto-x... I was wondering what i need spacer wise for the fronts with PBR dual piston calipers. And my car is a 97 so it has the little bit wider front track than the 94-95 cars. I want to make sure the wheels are the right offset to look right on the car, and not rub the caliper brackets.

Thanks