Hey guys, I'm looking for some advice from people who have experimented with different ratios in their cars. I'm wanting a little more pep from my 383, 4-speed, 28" tall tire, 3.23 Road Runner. It runs 2400 rpm @ 60 mph now and gets 12 mpg if I don't open the 4 barrels. What can I expect from a 3.73 setup?