Well here's the deal. I have a 350 bored .040 over, trick flow 23 degree heads, Comp cams .480 lift I/E cant remember duration or any other numbers of the top of my head, Victor JR. intake, speed demon 750 DP, complete MSD ignition. Any how the the cam builds power from 2200 to 6100 RPM and the whole set up is very strong in the mid to upper RPM range. I have a four speed muncie with a 3.73 posi out back. This car is boggy under 2000 RPM and I was wondering if switching to 4.10s would help much. It runs about 2300 rpm going down the highway. Im not concerned with fuel mileage and its just a weedend cruiser. Any way do you guys think this is a reasonable swap or should I stay with the 3.73's?