[84gt347]

I think maby 10 to 15 horsepower on the current mods. I dont think the chip will do much unless its an auto car, and then i still think it will only marginally improve the car. I think you can do headers and keep the warranty intack. Definately put in gears. 3.73, 4.10 either one. I.ll bet it'll lay down 13.9 like it is. Maby 13.7 or 13.6 with the gears and tires. I have gone 14.0 in a 2001 bone stock.