[3.4 grape of wrath]

What should your oil pressure be at idle? Between 20 and 40lbs at idle sounds about right. Having no oil pressure only once sounds odd, I would let that one go. I would rebuild the motor you have but first I would do a tear down and inspection than make my decision. As far as gears go for the street I wouldn't go any higher than 3.73's. Before you lower the car plan out all your parts first. If you lower the car you MUST change the springs and don't forget to adjust your pinion angle. You can either get an adjustable torque arm or use transmission mount shims to correct the pinion angle with a non-adjustable one.