Dont get a JET chip. They are freakin' garbage! Go with Superchip. I saw a 98 S10 4.3L on the dyno and he got 1 HP, and lost 2 ibs of torque. (1/-2) Then we installed a superchip and that same motor got 14HP and 27 pounds of torque. Seems unreal, but it had a lot better numbers.