I just put 35/12.50R16.5 BFG A/Ts on my 97' F150 4x4 4.6L.

I have the stock 3.55 gear ratio, but it seems that the tires barely stay up to cruise. If i go up the slightest incline it shifts hard into 4th. I have also lost some power and it is suckn down the gas.

-Should i change the gear ratio or leave it?
-How would a 3.73 perform, or higher but not as high as a 4.11?
-Do you have to change the front and the rear end and how does all this work if i am making any sense?
-Prices would help too!

Thanx

 

Your tire/wheel overall height is ******* you out. Yes, you should change the gears. Yes, you change the front and rear gears. The 4.6/8.8" allows for a few more ratio choices. 3.73s will suck, just like what you have; the performance increase is minuscule. With that overall height, you will need 4.30s to be near stock performance and if you want to increase performance, you'll need an even lower gear (higher numerically). Total installed cost should be ~$1,100-$1,400.

 

I agree, but I would go with 4.56 gears since your have a 4.6 liter engine.

 

I run 4.10s with street tires. You need these at hte very least, 4.56 will be much better.

It's not like the old days when musclecars had narrow-ratio trannies that would redline at 70 mph... These trucks have wide-ratio gearboxes so you'll be fine.

 

i also say 4.56

 

Thanx i think the 4.56 sounds good. Would it be possible to do it myself and avoiding the steep price or would taking it in be the better choice?

 

if you are not a pretty good mechanic i would take it in to a shop you need a few tools the shade tree mech does not have like a bearing press a backlash indicator and a micromiter, you will also need alot of pateince, i have done a few and it is easy once you have done it a few times

 

What happens if you only change the rear gears on a 4x4? Just curious.

 

very very very bad things will happen if you try to use 4 wheel drive dont attempt it