How many lug bolts hold the wheels on. If it has 6 you have a 1/2 ton. If it has 8 it is a 3/4 ton. All of the previous posts have assumed you had a 1/2 ton because you referred to a 3.55 gear set. There is no 3.55 gear set for a 3/4 ton. If it is indeed a 3/4 ton, the only practical way to go faster is an overdrive transmission. If you are not sure if its a 1/2 or 3/4 ton I think you may be getting ahead of yourself in your plans.
