80 Front Ttb Bronco Gear

[Giovanni]

Dear Friends,

I'm written from Peru in south america, I need your help!

I have an '80 Bronco with a 351M with some modifications, I want to put 33" tires on it and I have two questions:

1.- I think to change the gears to 4.11 but I don't want to loose power and milage as well.

Is that the correct ratio to get it??

2.- I disassembly the rear end and I found that the ratio is 3.50 on the 9"

What is the ratio for the front DANA gear in this truck?

Thank you very much for your help,

Giovanni Pierinelli

 

[freak]

The ratio for the front will be the same as the back.

 

[zakcode]

350's will do but 411's will do a little better keeping you closer to stock gearing...

 

[Justshootme84]

Giovanni, the front ratio is also 3.50:1. As much as it costs to swap gears, I personally would not change to 4.10:1 if you are only going to use a 33" tall tire. The stock gears are close enough for that size tire for normal driving, and the mileage difference is not that noticeable in my opinion. When you go to a 35" tire or need to do alot of towing or climbing hills, then it may be worth swapping to a 4.10:1 for 33" or 4.56:1 for 35" tires. I am running a 35x12.50R15 tire with my stock 3.50:1 gears. The speedometer is not correct, but I still have some power for offroad.

 

[Justshootme84]

Since youy have mostly desert, rocks and a few mountains, you may need the 4.10:1 gears eventually. I would first get the 33's and try them with your stock gears. After a few trips, you will know if you need taller gears or not. But I think it will still be a sublte or small gain to swap gears. Good Luck, and post your results!!!

 

[southerntrax]

i ran 33's with a 3.08:1 in my 84 with a inline 6. did good around town but kinda need more gear on the trails. just my 2 cents