The Zex kit is a great kit. I prefer the NOS mustang kit with a 100 hp nozzle. Be sure to change the plugs to copper plugs. Reprogram the xcal for two programs, one for MPG and one for NO2. You will want to either be saving gas or boosting with the funny gas. My $.02.

Sold 1998 Contour LX 13.868 sec 1/4 mile time. Two years of rental cars, seriously. Holding out for 07 Cobra Mustang.