About 4 years ago I broke the gears I was running and stuck some 3.50 gears in my D50 with 315/60 Drag Radials. I was surprised that it did not slow down very much. It ran a 6.39 at 109 crossing the finish line in 2nd gear in the 1/8. With a 1.39 60 ft. Wallace racing calculators says that is around a 10.10 in the 1/4. It is a 394 ci small block running on pump gas (93 octane) through the mufflers with No power adder at 2950 lbs.