I had my 73 dart on a chassis dyno this weekend. I have a 446, 9.98:1 compression, Mopar .557" lift cam, roller rockers, Eddy 84cc chamber aluminum heads, M1 intake, Holley HP750 carb, TTI headers and good flowing exhaust, 727 trans built with a 2400rpm converter, and 4:56 gears in the rear...