Originally Posted By BradH
Re MPH vs gearing, the difference between 3.55 and 4.10 when my car was in the 12s was negligible. It ran 12.4 at 112.7 with 3.55s and 12.2 at 112.7 with 4.10s. The MPH only changed when the tire & gear combination resulted in the engine over-reving, and then it dropped off by 2 to 3 MPH.


I fell into the "need deep gears!" trap at an early age. I blame it on a Chrysler Power article that had a chart showing progressively faster e.t.'s with deeper gears. Went from 3.23's to 4.56's behind a solid cammed SB in my Cuda. Car ran identical e.t. and mph. ...but with a lot more rpm on the street! Promptly pulled the 4.56's and sold them a month later..

'63 Dodge 330
11.19 @ 121 mph
Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs.
10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.