Quote:

i have a 71 duster it currently has a 383 auto 8-3/4 with 5.13 , 32x14 slicks, should i got to a smaller tire for the 1/8 mile or keep the same size that i have .i want to go thru the lights at around 62-6500 rpm, or would the smaller tire rev to fast for the 1/8th mile track.

seeing as gears are usually figured at 28 inches right now your 5.13 is actually a 4.46 gear,and with the 28 would be a 5.13, but if you wanted to see your rpm difference ,add approximately 13% to what you do in the 1/8 now.but can your car leave with the smaller tire[due to higher gear ratio] bob