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3rdMAN
12-14-2012, 01:27 AM
i was wonderin what the final gear ratio would be if i run a 6.66 rear gear with a th350 in 2nd gear thanks for any help

istock11m
12-14-2012, 07:13 AM
2nd in a th350 is 1.52. 1.52x6.66= 10.12.

ToddSmith16
12-14-2012, 08:03 AM
are we running a go cart track?

3rdMAN
12-14-2012, 09:00 AM
no its a car track. i didnt know if it was a different way to find the ratio in a ford rearend & a chevy we ran a 4.56 in a 10 blt which is a 6.93 we are changeing to a 9 inch the 1 we got has the 6.66 didnt know if i needed to change it the track is a 3/8 banked track

ToddSmith16
12-14-2012, 01:03 PM
Just run it final drive 1:1...easier on trans anyways. Whatever gear is in rearend will be your final ratio...gears available are 6.66, 6.83 and 7.0 which is close to your previous final drive.

CLAWS44
12-14-2012, 03:51 PM
if its a 3/8 mile 6.66 gear is way to much you'll be killing your motor, try a 6.00 first

Driver88
12-15-2012, 08:57 PM
if its a 3/8 mile 6.66 gear is way to much you'll be killing your motor, try a 6.00 first

Not necessarily we have 2 ⅜ tracks close by and ya can run a 683+ (depending on class) and a 600-620 at the other. Depends on where they measure the ⅜ at I guess.

little302
12-17-2012, 03:43 PM
Im with the 6.83 guys.. we do it on a 1/4 3/8 and have no problem. What does the car weigh? 3200, 3000, 2500? It all makes a diff.. Keep in mind you will have some TQ conv slippage which does change your final ratio.. Not by much, but enough to warrant knowing..Also.. where do you run on the track? Bottom middle, top? What RPM do you normally turn? Does your cam allow you to turn more? And remember... final drive is always the product(multiply) of two numbers trans gear x rear gear. Rear gear is always ring gear teeth divided by the pinion gear teeth..ie. 41/10= 4.10 or 39/13=3.00. if you have a good torque motor the 6.66 should be ok. But.... ask your self the above questions and GET answers..