I work at a ford dealership, i think i can get parts cheap enough. should i change my gear to 3.55 to "out accelerate a Yugo"? specs below.

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2000 Expedition 4.6 3.31 Rear
AIRAID Fipk with Poweraid Spacer
UltraFlow muffler
82 mm Mass Air Flow Sensor

 

Go for the 3.73 you will feel more in the seat of the pants dyno and your gas mileage will still be okay.
Should be the same price.


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97 F-150, 2WD, Reg Cab,Flareside,Dk Toreador Red, Windsor 4.6, Magnecor 8.5mm wires, Bosch Plat +4s, 3.55 LS, EGR Bug Deflector, ******* Bed Cover, Bed Liner, XL Full Length Running Boards, Air Aid Kit, Gibson Single Out Cat Back, Superchips, TransGo Shift Kit, Hellwig Rear Sway Bar, Hellwig 2500# Overload Springs,Energy Suspension Polyurethane Front Sway Bar Bushings, 265 70 16 tires, Rancho RS9000 shocks

 

.25 or so ratio change is not very noticeable. It is much more noticeable and worthwhile at a minimum of .50 or so. You may also want to consider what height tires that you will install/prefer in the future to factor this in as well. Did you ever consider 4:10s?

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2000 F-150 XL, RC, LB, 5.4L, 4R70W, 3.55LS,
Class III tow, Payload #3, & Convenience pkgs.,
4-wheel disc/ABS, Chestnut/Parchment 40/60,
Ford bedliner w/Paintsaver & gas/wheel/spare locks,
K&N F.I.P.K. w/Outwears pre-filter, Superchip,
Dynomax ultra-flow welded 3" cat-back w/ 3" Y-pipe,
Hellwig front & rear anti-sway bars, Rancho RS 9000s,
Mobil 1, K&N oil filter.

 

4.10 might be too big of a jump. i just want a good take off. i'll inquire on the parts. thanks for the info.

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2000 Expedition 4.6 3.31 Rear
AIRAID Fipk with Poweraid Spacer
UltraFlow muffler
82 mm Mass Air Flow Sensor

 

Hey Newbie 46,

I wopuld recommend 3:73's instead of 3:55's. You may feel some difference from the 3:31's but not enough.

I had the 3:55's in my truck and change to the 3:73'S recently. RPM increase was 500 rpms more for gear, quicker feel, and really hasn't effected my gas mileage.

4:10's would be a great choice if you put larger tires on or you are out to do a lot of drag racing or heavy towing. 3:73's are about average for performance and towing.

 

thanks crazyaboutf150, i'll check out the prices tomorrow. if you don't mind, how much did it cost you?

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2000 Expedition 4.6 3.31 Rear
AIRAID Fipk with Poweraid Spacer
UltraFlow muffler
82 mm Mass Air Flow Sensor
6.8 inch TV with tuner/VCP
Full alarm and Auto-Start
Daytime Running Lights

 

Hi Newbie46,

I bought my gears through my local Ford Dealer. They purchased them through Ford Motorsports.

I don't have my receipt at home, it at work (hiding it from my wife), and I believe the gear was $450.00 or so. Pretty expensive! The total cost with labor was $962 and change. My dealership changed the gears.

I would look at availability for 8.8 gears from additional sources. I had seen them available for around $200.00. Maybe not the quality Ford Motorsports has or I was taken to the bank by my dealer.

Anyway, everything went great! My truck was in the shop for about a half a day. If you decide that the 3:73's aren't for you, I've got my 3:55's in the box. Just let me know.

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'00 F150 SC w/ 4.6L, Oxford white, Gray Int., leather steering wheel, Lariat/4x4 fender lip molding (painted Oxford White), GTS slotted tailight covers (painted Oxford White), Lariat front grille/headlight assembly and front bumper cap (painted Oxford White), lower factory bumper w/ driving lights, Ford billit hitch cover, Line-X-bed, and a carbon fiber hood bug deflector.
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Performance: 75mm BBK throttle body, Poweraid spacer, Granatelli 80mm MAS, K&N Generation II intake system, ASP pulleys, 2-16" Hayden Rapid Cool electric fans, Gibson headers and cat back exhaust (split rear) 3:73 rear gears, and a custom Superchip.

 

Moving to 3.73 from 3.55 was barely perceptable to me -- and is roughly the same percentage difference as that which you are contemplating.

Re-visit Max's suggestion.

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Y2K™ 7700 4x4
Jim - N8JG@Hotmail.com

Toreador Red, Keyless XLT SC SB 5.4L E4x4 4wDisc/ABS, 3.73LS, Skid, HD 7700# Towing, LT-245's on Chrome, Tube-Steps, Captain's, 6CD, Tonneau, named: "Nick"

 

Hey jgorka,

You're right about my gear change. When I was comtemplating what gear I wanted, I ask around quite a bit, including my Ford Dealer. I wasn't looking for just street/strip performance but, overall improved performance when just driving and towing.

My truck will never see larger/taller tires on it, except the 295/18's like on the Lightening. If Newbie46 wants to install taller tires, keep or improve his performance times, then I would opt. for the 4:10's.

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'00 F150 SC w/ 4.6L, Oxford white, Gray Int., leather steering wheel, Lariat/4x4 fender lip molding (painted Oxford White), GTS slotted tailight covers (painted Oxford White), Lariat front grille/headlight assembly and front bumper cap (painted Oxford White), lower factory bumper w/ driving lights, Ford billit hitch cover, Line-X-bed, carbon fiber hood/ bug deflector.
-------------------------
Performance: 75mm BBK throttle body, Poweraid spacer, Granatelli 80mm MAS, K&N Generation II intake system, ASP pulleys, 2-16" Hayden Rapid Cool electric fans, Gibson headers, Gibson cat back exhaust (split rear) 3:73 rear gears, custom (flip chop) Superchip.
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Future mods.: white face guages, 2/4 drop kit, Lightening 18x9.5 wheels, 295/18 Z rated Goodyears, fiberglass toneau cover, Stillen front bumper cover, MSD or Jacobs electronic ignition upgrade,

 

did not get a chance to check out prices for the gears. if the gears are about 450 or so then that is all its gonna cost me (hopefully), since i trade jobs with the mechanics. ( i run the alarm dept). anyway, i'll try again tomorrow. just curios crazyaboutf150, how much would you like for your 3.55s?

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2000 Expedition 4.6 3.31 Rear
AIRAID Fipk with Poweraid Spacer
UltraFlow muffler
82 mm Mass Air Flow Sensor
6.8 inch TV with tuner/VCP
Full alarm and Auto-Start
Daytime Running Lights

 

Hey Newbie46,

I'll let them go for $200.

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'00 F150 SC w/ 4.6L, Oxford white, Gray Int., leather steering wheel, Lariat/4x4 fender lip molding (painted Oxford White), GTS slotted tailight covers (painted Oxford White), Lariat front grille/headlight assembly and front bumper cap (painted Oxford White), lower factory bumper w/ driving lights, Ford billit hitch cover, Line-X-bed, carbon fiber hood/ bug deflector.
-------------------------
Performance: 75mm BBK throttle body, Poweraid spacer, Granatelli 80mm MAS, K&N Generation II intake system, ASP pulleys, 2-16" Hayden Rapid Cool electric fans, Gibson headers, Gibson cat back exhaust (split rear) 3:73 rear gears, custom (flip chip) Superchip.
-------------------------

Future mods.: white face guages, 2/4 drop kit, Lightening 18x9.5 wheels, 295/18 Z rated Goodyears, fiberglass toneau cover, Stillen front bumper cover, MSD or Jacobs electronic ignition upgrade,

 

500 rpm jump from 3.55 to 3.73? I don't think so. Thats only a 5% difference in ratio. For instance, if your old cruising rpm at 70mph was 2000 with 3.55s, new rpm with 3.73s would be 2101.

Newbie46,
From 3.31 to 3.73 is still only 11% difference, so a couple hundred rpm on the freeway, and that won't have much effect on gas mileage. What *might* effect mileage negatively is the fact that the truck will feel sportier, and you're likely to romp on the gas more often. If you want to compare what rpm you'll turn with any gear, simply take rpm at any certain mph, divide by current gear ratio, multiply by the new gear ratio, and thats what your rpm will be at that speed.



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2001 x-cab 4x4

1993 Mustang LX hatchback, 10.46 @ 131.60

1997 Cobra for sale

 

Hey '01BlackF150,

I could be wrong on the rpm's. I forgot that when the gears were changed, the service manager told me that the computer would compensate for the change and correct the speedo.

Not so! Mike T. said that it could be corrected through the custom program with the Superchip.

I need to verify my speed with the rpm's again with the speedo corrected. I'll have the info tomorrow.

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'00 F150 SC w/ 4.6L, Oxford white, Gray Int., leather steering wheel, Lariat/4x4 fender lip molding (painted Oxford White), GTS slotted tailight covers (painted Oxford White), Lariat front grille/headlight assembly and front bumper cap (painted Oxford White), lower factory bumper w/ driving lights, Ford billit hitch cover, Line-X-bed, carbon fiber hood/ bug deflector.
-------------------------
Performance: 75mm BBK throttle body, Poweraid spacer, Granatelli 80mm MAS, K&N Generation II intake system, ASP pulleys, 2-16" Hayden Rapid Cool electric fans, Gibson headers, Gibson cat back exhaust (split rear) 3:73 rear gears, custom (flip chip) Superchip.
-------------------------

Future mods.: white face guages, 2/4 drop kit, Lightening 18x9.5 wheels, 295/18 Z rated Goodyears, fiberglass toneau cover, Stillen front bumper cover, MSD or Jacobs electronic ignition upgrade,

 

hey guys, i've decided to stay with the 3.31 after all i can squeak the tires from dead stop with this gear ratio. i was told unless i upgrade to 4.10 i might as well spend the money on the chip. by the way, ford is coming out with their own "powerchip" i am curious and excited as to what it can do.

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2000 Expedition 4.6 3.31 Rear
AIRAID Fipk with Poweraid Spacer
UltraFlow muffler
82 mm Mass Air Flow Sensor
6.8 inch TV with tuner/VCP
Full alarm and Auto-Start
Daytime Running Lights