My weekend driver is 1972 Charger Rallye 340 automatic with 3.23 gears. I'm looking for more low and mid-range torque as it's more a cruiser than a racer. The car has a set of exhaust manifolds from a 1970 340 and 2" full length pipes with no crossover. I plan to install a crossover, but would I see an improvement going with 2 1/4" or would I be best staying with what I have. My car rarely see's anything above 4000 rpm.