Gear Change?
 

I am currently running 580 cu in,32 in tires, powerglide 1.76 1st gear, 4.56 gears with 6.47 1/8 mi time. i have a set of 5.38 will these improve my et or should i just leave things alone.Thanks for your input

More info? what is it in? cam profile? somethings not rite, a 580" and a 6.40?

I agree with KW, that thing is way off base at 6.47 with that many inches. It should actually like a 4.56 gear due to the torque of an engine that big. There's definately someting else missing here, that should be a 5. sec car.

JMO

Zip.

580
 

This motor started out as a blower motor on NOS in a tunnel hull dragboat, static compression ratio is 9.2-1, 4 in throw on crank, mild cam only about 640 lift,I sold the blower setup when i bought this car becuase i have a hard time lifting the throttle and want seat time in a car before graduating up in HP.So I bolted on a good single plane intake with a 1150 dom and now have a good Pumpgas motor for the track, Off the line it picks the front wheels about 10in high and carries that stance for about 30 feet,i should have given you more info I do agree with more comp and different cam this would be a 5 sec car, i do have fuel pump issues on the big end and when i get that resolved i should be in the 20s. i just have the 5.38s layin around and thought i get your thought on a change.Again Thanks for your input

How heavy is the car? What does the converter stall at? What are your rpm's at the stripe?