BlackThundah

The title basically says it all. I'm getting the truck regeared before I lift it. I've been reading a good bit on the internet, searched the forum, and I'm still undecided. I really wanted to go ford racing, but unfortunately they don't make the reverse cut for the front. Still can't make up my mind, to go with either 4:10/4:11 or 4:56. I'll be running 35s with the 4.6. From what I understand 4:10s will make it a stock ratio and 4:56 add a little pep. Just not sure if i can get away with the 4:56 with 33s till I lift it. I can't decide on a brand either, it seems like yukon is hit and miss. Some people love them, some have a hum. Any body that knows about them please help me out. Any help as always is much appreciated.

Red-Ford

I looked into this a while ago, I'm running 35's and I was going to do 4.56 Yukons with either a Detroit or Spartan locker.

One guy told me 4.56's with stock tires (I was thinking about downsizing to 265's for winter so I wanted to know if that was alright) would be fine. He brought up the point that the stock ratios for these trucks are 3.55 and 3.73 which is a 0.18 difference, 4.10 and 4.56 is a 0.46 difference, which is only 0.28 different from stock. He also added that the heavier trucks (superduty's) go all the way to 4.10's for towing and they are on small tires. He also said a lot of people have the bigger gears and smaller tires for racing.

UtahGuy

Maybe this will help? http://www.grimmjeeper.com/gears.html


Assuming a 4R70 and 70MPH:

• 33 inch tires, 4.10 diffs, 2046 RPM
• 33 inch tires, 4.10 diffs, 2275 RPM
• 35 inch tires, 4.56 diffs, 1929 RPM
• 35 inch tires, 4.56 diffs, 2145 RPM

Get the 4.56s - do not fear the gear. Even with 33 inch tires and 4.56 gears and doing 85 MPH, your RPM will still only be 2763. By way of comparison, with stock 265/70r17 tires and 3.77 gears, your RPM at 80 MPH is 2384.

jstockert

Go with Yukon 4.56 and never look back. I did in my 97 f150 and love the setup. My brother is into drag racing and he has always run Yukon gears. He has a 1971 Chevrolet chevelle with a 454 with a blower and runs mid 10's in the quarter so they are strong also. A bit of advice while you have your diffs torn apart go ahead change all bearing and seals. Also the clutch pack in your carrier if your not getting a new one. Don't forget the tsb for syn 75w-140 gear oil just under three quarts for back and I think just under two for the front. And friction modifier. You can call Randy's ring and pinion and they set you up with everything you need. Great customer service. Hope this helps.

BlackThundah

Thank you guys for all the help! Looks like i'll be going with the yukons.