I've got a 1990 F-150 4x4 w/351W. It currently has 3.55s w/posi. I'd like to put in 3.73s to get some more pulling power. Though I've been told that the front has to be changed too. What gear ratio should go up front? Can this be done? How? It's got E4OD trans. Just replaced the torque converter too. About 2000 miles on newly rebuilt 351W, 96000 miles on the truck/trans. I pull a gooseneck and some smaller trailers with this too. What do ya'll think? I only get about 10.5 mpg with this hog as it is.

[This message has been edited by MO4x4 (edited 02-10-2000).]

 

Front gear ratio should always match the rear ratio on street driven 4x4s. Otherwise, the transfer case is attempting to turn the driveshafts at two different speeds. NOT a good thing for longevity.

 

Actually, Nomo is correct, but our 3.55's in the rear, and 3:54 in the front. I condemplated doing the same, but it would cost over a grand to do it, and I decided to rebuild instead.

 

4.10s front 219.95
4.10s rear 199.95
Labor 375.00
Auburn LS 359.95
Bearings 95.00
Install kit 29.95
Syn. fluids 82.95
S&H 28.15
Tax 78.20
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Total 1469.10
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Prices are for the Expedition. Older trucks should be a little cheaper. Also note that the price includes limited slip in the rear.


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1997 4x4 Expedition- 4.6L, true dual exhaust w/glass-packs, K&N air filter, SuperChip, airbox mods, Edelbrock shocks, 285/75R16 BFG ATs, Optima "T-Bone" wheels, 4.10 gears, Auburn LS, Clarion In-dash CD player, Smitty Bilt push bars and nerf bars!!

2000 4x2 F150 XLT Reg. Cab LWB- 5.4L, Tow Pkg, 3.55LS, CD player,Remote Keyless Entry, Sliding back glass, Special Appearance Pkg.

http://members.visualcities.com/NoMo

 

I read that Summit Racing is selling Richmond gears with 1.626" pinion stem

3:55's;189.95
3:73's;189.95
4:10's;185.95
4:88's;199.95

 

so you are saying that both the front and rear are 3.55s? so if I put 3.73s in the rear and the front that would work, correct? I think I understand but I'm not sure. Thanks for the help.

 

MO4X4,
stay away from Richmond gears. When I had mine installed every company I talked to said staw way from the Richmond gears. poor quality and they create lots of
gear meshing noise. I have never heard a set of these gears in action, but it was funny to hear simiular stories from almost everycompany I called. Well except for the stores that SELL Richmond gears. I always say you get what you pay for, and when installing something like gears, and in your case, 2 sets of them, I would go w/ a well known brand. I can recommand a great set of gears. US/STRANGE gears, are made in the USA and are hardend steel.

good luck,

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

 

MO4x4:
For a lot of good info, visit www.ring-pinion.com

 

I have a 89 F-150, it's front Diff has a 3.54 gear ratio, and the rear is a 3.55.