I have checked on gears for the V6. Here is what I was told:
31" tires in 3rd gear at 70 mph with 4:11 gears is 2500 rpms, with 4:56 = 2750 rpms.

So if you have 31" tires your best bet might be 4:11.
I have 31" tires with 3:55 gears and HATE IT!! I get abot 21 mpg on the highway and only 10-11 mpg around town. With 4:11 i'll get an average of 15-18 mpg. I will be making the upgrade real soon. This should compliment my Nitrous kit real well
The upgrade to 4:11 gears with limited slip will run around $1000. Ill post when it gets done.


------------------
Ed

• '97 F-150 2wd 4.2 Auto, Supercab
• 265/75 R16
• Catback system
• Airtornado
• K&N system
• 3.55 gears
• Superchip
• 10 disk CD Changer
• Soon to 100 shot of NOS, 3" lift kit and 4.11 gears.

 

Dude, if you go to 4.11 gears, your mpg will decrease. Think about it, if you are currently doing 2500 rpm at a given speed, and with the 4.11's you are going to be doing 2750 rpm. Your engine will be spinning more and hence using more fuel.

------------------
2000 Silver F-150 XL Sport
Reg. Cab, Reg. Bed, 4.2L V6, 5-speed, 4x2

mods:
Tailgate lock, Generic bedliner, coyboy antenna ball
285/75r16 BFG AT ko (33.1x11.4)
Sony CD player, Blaunpunkt 5.25" speakers
Crimeguard alarm, Power locks

future:
1" coil spring spacer
new rims

dreaming:
true dual exhaust with flowmasters
RCD 5" lift, 315/75r16 Yokahama Geolander MT(34.9x12.6)
---------------------
Never let your schooling interfere with your education --Mark Twain

 

He didn't say he is doing 2500 now he said he would be with the 4.11's, be a good improvement over his 3.55's.

 

Thats right - right now I have to floor the truck until about 30 mph. When I get the 4:11s i wont have to do that( thus bringing up my gas mileage around town) I will see a decrease on the highway - but that is ok. My all around gas mileage will be greatly increased with this change.


------------------
Ed

• '97 F-150 2wd 4.2 Auto, Supercab
• 265/75 R16
• Catback system
• Airtornado
• K&N system
• 3.55 gears
• Superchip
• 10 disk CD Changer
• Soon to 100 shot of NOS, 3" lift kit and 4.11 gears.

 

hey, how much taller are those 265/75/16 over the stock 255/70/16. i would like to put a set on mine and then raise the front 1" with coil spring spacers

 

I went from 255/70/16 to 285/75/16 on my 4x4 truck. Fortunately I have a manual tranny and it helps compensate a little but I miss the power I had before. I want to go ahead and swap out my gears, BUT I know that eventually I'm gonna lift and put on at least some 35 ( 315's) so If I go ahead and swap in 4.56's (anticapating the 315's) how bad off am I going to be untill then? I don't have a tach in my truck so I have no idea how much rpms I'm turning to begin with!
But I do know that I have to swap my gears!

------------------
Y2K F150 4x4 XL Med Torredor Red
4.2 5 speed,AIRAID, SuperCHIP,
3.55 LS, Leer camper shell, bedrug,
Ranchhand Rover Brushguard with 6 LIGHTS and
Wireless remote switch Tint/alarm/ aftermarket keyless entry/locks
2m/10m/11m/12m radios, Scanner
LT285/75/16 BFG All Terrains
regulator@f150driver.com