hardtohitme7

need help asap- my buddy is ordering new gears for his nova, the car is driven short distances on the weekends and to the track. hes stuck in between 4:10's and 4:56 gears. he has a munchie 4 speed and a 597 lift roller cam with rpm range of 3500-7000. hes afraid that he will run out of gear at the end of the track. i told him to go with the 4:56's. lemme know what you think

Domestic Demon

iTrader: (1)

Well it depends on what the gear ratios are in his 4 speed.

If 1st gear is about a 2.75 or above, I'd go with 4.10's. If its a 2.5 or below, I'd definitely consider the 4.56's.

Just beware that 4.56's are a LOT of gear, that thing will be ripping through the gears as fast as you can shift it, and traction may also present a problem

Villain281H

iTrader: (5)

I'd say 4.10s. 4.56 will be a major bitch on the street. I run 3.73s and a 28" tall slick and go through the traps at 6 grand in my Nova on the motor, and depending on his tire choice and how fast the car runs, the 4.56 gears will also hit VERY hard off the line so traction could be limited.

Derek

67SS&99SS

iTrader: (7)

I've got 3.73s with a Muncie M20 4 speed, 2.52 first gear and its winding about 2800-3000 going down the road at 60 mph. I've got a 255/60/15 tire. I personally wouldn't go any lower than a 4.10. Traction will be a big issue with a 4.10 and you can pretty much forget it with a 4.56. If he has the close ratio M21, or rock crusher M22, then he may be able to get away with the 4.56 because those transmissions have a 2.20 first gear. I wouldn't do the 4.56 with a M20 though. You want to be around a 9-9.5 overall first gear ratio.

My setup: 3.73 gear*2.52 first gear =9.40 overall

M21 or M22 with a 4.10 gear = 2.20*4.10=9.02 overall
M21 or M22 with a 4.56 gear = 2.20*4.56=10.03 overall
Find out what muncie he has and that will help determine the need for the final overall gear. 69-74 muncies have a code stamped on the case that includes the letter A, B or C. A is a M20, B is a M21, and C is a M22. Hopefully this will help you out.

johnjzjz

I am going to tell you go to richmond gear site and they have a gear slect on line chart its not perfect but if your motor makes what you think it does the chart will work for you be conservative on the power put in what it does now get that HP # and use it for the change jz