Mud Racing 1979 ford gearing setup ????

1979 ford shortbox , 44 front 9 rear. 205 tcase, c6 trans.... 38 skinny boggers.... 180 length mud pits 8-18 inch deep... playing around with gears... What differential gears are some others running?

I run 5:13's front and rear

in high or low range?

Me too, in low range. Made the swap from the 38/39.5 combo to 42" boggers and I'm noticeably faster this year.

kjett wrote:Me too, in low range. Made the swap from the 38/39.5 combo to 42" boggers and I'm noticeably faster this year.

I'm not at all trying to start a keyboard battle I'm just trying to figure out the gears for my new build. You have always pushed the 10:1 final drive and not wheel speed. With My 466 I ran a 10.47:1 and it worked very well. But if you went from a 39.5 to a 42 you changed the ground speed (mph) by at least 5mph if you are turning the same rpm. I am going from a 466 to a 545 or 557, so with the increased torque and prob few hundred less rpm I cant see the same final drive working as good.

I still do. I've said don't sweat the wheel speed as much as getting the final drive ratio correct. By me going to the taller tire, I still have my 10:1 final drive, I just increased the ground speed by going with the taller tire that has a longer roll out. Clear as mud?

Does anyone run highrange?

kjett wrote:Me too, in low range. Made the swap from the 38/39.5 combo to 42" boggers and I'm noticeably faster this year.

You changed from the 5.43's?

What kind of hp do you think you are putting out?

is going from 4.88 to 4.10 a really big jump?

Do you have the horsepower to turn the tire in the mud and not bog down in rpm?

Pretty sure I told you what gears I use to run and won't say on here again but try it you will be very surprised. It's not the gears or the transmission or the tire size or the motor size that matters!   It is all of them put together in a combination with a good suspension that will make your truck fast!!!!  My best advice is change one thing at a time and log your results to see where your at and when you find the combo that you think works keep changing small things, even try some old parts over because once one thing changes ten others may need to be adjusted to get optimal performance from it.  But always keep records of your changes and what they did to the truck!

lghting94 wrote:Pretty sure I told you what gears I use to run and won't say on here again but try it you will be very surprised. It's not the gears or the transmission or the tire size or the motor size that matters!   It is all of them put together in a combination with a good suspension that will make your truck fast!!!!  My best advice is change one thing at a time and log your results to see where your at and when you find the combo that you think works keep changing small things, even try some old parts over because once one thing changes ten others may need to be adjusted to get optimal performance from it.  But always keep records of your changes and what they did to the truck!

sent you a pm lghting94