3.55 to 4.56 Gear Swap Complete!
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Y2K 7700 4x4,
When we picked up our truck from the dealer, it had 14 miles on the odometer. I can guarantee those 14 miles weren't driven all at once but in different stages of transport.
F&B's
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98 F-150 XLT, SC, SWB, 2WD, Pac. Grn., 4.2L auto, 4.10 gears w/ LS, Tow Pkg., BFG AT's 265/75/16, K&N air filter, Dynomax muffler, Superchip, Edelbrock shocks, Hellwig sway bar, 3" body lift, signal mirrors, ...tons of cosmetic products
When we picked up our truck from the dealer, it had 14 miles on the odometer. I can guarantee those 14 miles weren't driven all at once but in different stages of transport.
F&B's
------------------
98 F-150 XLT, SC, SWB, 2WD, Pac. Grn., 4.2L auto, 4.10 gears w/ LS, Tow Pkg., BFG AT's 265/75/16, K&N air filter, Dynomax muffler, Superchip, Edelbrock shocks, Hellwig sway bar, 3" body lift, signal mirrors, ...tons of cosmetic products
Rogueford:
I had the work done at First Capitol Four Wheel Drive in St. Charles. Cost me 1,075 for both axles. My truck is two tone Black over a light tan with the Lariat package (does not have the ORP stickers).
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98 F-150 4X4 Ext Cab ORP 4.6L, 4.56 Gears, Superchip, Gibson Cat Back Single exit exhaust, TransGo Performance Shift Kit, K&N Filter, Downey SST Tonneau, Abbot Electronic Ratio Adapter. Future: shorty headers.
I had the work done at First Capitol Four Wheel Drive in St. Charles. Cost me 1,075 for both axles. My truck is two tone Black over a light tan with the Lariat package (does not have the ORP stickers).
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98 F-150 4X4 Ext Cab ORP 4.6L, 4.56 Gears, Superchip, Gibson Cat Back Single exit exhaust, TransGo Performance Shift Kit, K&N Filter, Downey SST Tonneau, Abbot Electronic Ratio Adapter. Future: shorty headers.
For those of you who were wondering about the fuel milage with this new setup here it is:
3.55s with Superchip=15.26 mpg average over a 10 month period (mixed city and highway). Highest mpg recorded in the above average was 16.23 mpg!
4.56s FIRST tank with Superchip=15.8 mpg (included about 60 miles in town, about 20 minutes of hill climbing on the farm, then the balance on the highway at 65 mph on hilly terrain).
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98 F-150 4X4 Ext Cab ORP 4.6L, 4.56 Gears, Superchip, Gibson Cat Back Single exit exhaust, TransGo Performance Shift Kit, K&N Filter, Downey SST Tonneau, Abbot Electronic Ratio Adapter, Black Westin Nerf Bars. Future: shorty headers.
3.55s with Superchip=15.26 mpg average over a 10 month period (mixed city and highway). Highest mpg recorded in the above average was 16.23 mpg!
4.56s FIRST tank with Superchip=15.8 mpg (included about 60 miles in town, about 20 minutes of hill climbing on the farm, then the balance on the highway at 65 mph on hilly terrain).
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98 F-150 4X4 Ext Cab ORP 4.6L, 4.56 Gears, Superchip, Gibson Cat Back Single exit exhaust, TransGo Performance Shift Kit, K&N Filter, Downey SST Tonneau, Abbot Electronic Ratio Adapter, Black Westin Nerf Bars. Future: shorty headers.
I am planning a gear swap on my 2001 Expedition. I am putting a 6" lift on it and already have that planned out.
Is there anything special about the front 8.8 dif. that I should know about before ordering the 4.56 gears? I.E. Reverse cut, standard cut. Has anyone done this, and if so did you use the same gear cut and pinoin diameter front and back?
Thanks
Is there anything special about the front 8.8 dif. that I should know about before ordering the 4.56 gears? I.E. Reverse cut, standard cut. Has anyone done this, and if so did you use the same gear cut and pinoin diameter front and back?
Thanks
Originally Posted by mcexpo
I am planning a gear swap on my 2001 Expedition. I am putting a 6" lift on it and already have that planned out.
Is there anything special about the front 8.8 dif. that I should know about before ordering the 4.56 gears? I.E. Reverse cut, standard cut. Has anyone done this, and if so did you use the same gear cut and pinoin diameter front and back?
Thanks
Is there anything special about the front 8.8 dif. that I should know about before ordering the 4.56 gears? I.E. Reverse cut, standard cut. Has anyone done this, and if so did you use the same gear cut and pinoin diameter front and back?
Thanks
Originally Posted by kevin 3636
i have 3.55 with a 4.6L and bigger tires.they took my 3.55 to a 3.38.i lost power a 1 mpg.i put headers exhaust,KaN fipk,t- body spacer,chip,jacobs ignition.the power now is great,i was going to chang to a 4.30 or so,but when i priced it at$1500,i said no way .i can buy a powerdyne supercharger for $2000.why did you chang the gears instead of putting on a supercharger.how much more take off does the truck have now.
I would not reccomend skipping the gears for a supercharger if going with bigger tires, you are just trashing your tranny at that point my as well just pour sand in the tranny filler tube
As we speak my truck is under the knife for 4:10's I was talked out of 4:56 by the owner of the shop who knows his sheet, I am running 33's and don't intend to go higher my wife needs a ladder to get in it now
I have an 2002 f150 5.4 w/ 6" fabtech and 3" bl and 39.5 irok radials and just had 4.56's put in from 3.55 and I am running in od 1800 @ 70 and get about 13.5 city and 15 hwy.
5.4 superchip,magnaflow cat-back, 4.56's with locker, kn 77 intake, tb spacer
5.4 superchip,magnaflow cat-back, 4.56's with locker, kn 77 intake, tb spacer
Originally Posted by bigtruck311
the front you will need for a 8.8 IFS rev ring and pinion
Also I am planning on replacing the fluid with Amzoil fluid. Anyone used that before? I have heard many good things about their engine oil and tranny fluid, didn't know much about the gear oil.
Last edited by mcexpo; Mar 1, 2006 at 12:47 PM.
I am planning a gear swap on my 2001 Expedition...Has anyone done this?
Is there anything special about the front 8.8 dif. that I should know about before ordering the 4.56 gears? I.E. Reverse cut, standard cut...I can do the work
Amzoil fluid. Anyone used that before?
Last edited by max mitchell; Mar 1, 2006 at 06:25 PM.
Hey Sxnate,
Do you have any pics of your truck? It sounds pretty sweet I'd like to see it!

1999 F-150 XLT, 4x4, 5.4L, Super Cab Short Box, 3:73LS, 4R70W Trans.
Kool Blue Air Filter, Powerdyne TB Spacer
Flowpro Powerpack Si/Do w/ 4" Magnaflow SS Tips
3 Inch PA Body Lift
315-75-R16 Mastercraft Courser Mt's
Eagle Alloy 101 Series 16x10" Wheels
2 15" Rockford Punch P2's w/ Sony 1200w Amp
And Much More!
My Gallery
https://www.f150online.com/galleries....cfm?gnum=7219
Do you have any pics of your truck? It sounds pretty sweet I'd like to see it!

1999 F-150 XLT, 4x4, 5.4L, Super Cab Short Box, 3:73LS, 4R70W Trans.
Kool Blue Air Filter, Powerdyne TB Spacer
Flowpro Powerpack Si/Do w/ 4" Magnaflow SS Tips
3 Inch PA Body Lift
315-75-R16 Mastercraft Courser Mt's
Eagle Alloy 101 Series 16x10" Wheels
2 15" Rockford Punch P2's w/ Sony 1200w Amp
And Much More!
My Gallery
https://www.f150online.com/galleries....cfm?gnum=7219
Last edited by 99fordman; Mar 10, 2006 at 12:52 AM.
So what exactly would be needed (and aprox how much) if I were to put 4.10s in my 2003 4.6 Expedition. It is not 4x4, if that matters.
I'm guessing that any smaller than 4.10 would not be of much use, right?
Just trying to get the Expy to take off a little quicker
Thanks in advance.
I'm guessing that any smaller than 4.10 would not be of much use, right?
Just trying to get the Expy to take off a little quicker

Thanks in advance.


