Hi I just got new tires that are 33 inches tall and I can tell there has been a loss in performance but I am not sure what new gears to get. I think that I have 3.55's right now and I just want to know what # gears I should get to regain the peformance and maybe add a little more.

------------------



1999 F150 REG.CAB BLACK 2WD SPORT 4.2 LITER V6

• FLOWMASTER SERIES 40 DUAL EXHUAST
• K&N Filter Injection Performance Kit
• MANIKS GRILLE GUARD
• PIONEER DEH-P4000 CD PLAYER WITH 4 3WAY SPEAKERS
• SPIDERGEAR BED WEB
• PROCOMP HEADLIGHT & TAILLIGHT BLACKOUTS
• 1.75 INCH COIL SPACERS(gave me 3 inches of overall lift).
• 3 inch body lift
• 33x12.50R16(305/70r16) Procomp Mudders
• 16x8 American Racing BAJA rims

-------------

-------------
JDsF150@austin.rr.com







[This message has been edited by JDm (edited 07-15-2000).]

 

The 3.73s would most likely get you close to a stock feeling. If I were to change out gears for 33" tires, I would run 4.10s. 4.56s for 35" tires.

 

I have a '97 4.6 that had 3:55 gears. After going from 255-70-16 OEM tires to 285-75-16, the loss of power was noticeable, even with the Superchip, but what was more important to me, the fuel consumption skyrocketed.(not to get into the speedometer being off) So I went to 4:10 gears and I got the power back and the mileage is back to 17+ and the only tradeoff is a small amount of gear whine. I now realize that if I had gone with 3:73's like I originaly planned, would have been a mistake and I would have ended up changing them again.
Roberto

------------------
'97 F150 XLT SC, 2WD, 4.6 Auto, 3" Bullseye spindles, 2" blocks in rear, Rancho RS5000's, AR Baja's 16X8, 285-75-16 Firestone Wilderness AT III's,
Donmar Sunroof, Sony CD player, SuperChip, K&N Filter, Weathertech Ventvisors, Ford locking gas cap, Delta aluminum toolbox,
Putco shorty chrome bedrails, 4:10 US Gear ring & pinion, complete with gear whine. (It's the Turbo, Son, it's the Turbo!)

 

JDm, nice truck! I had the same problem going to the 285/75's with the 4.6L. I have looked into this a little but when I asked the local ford dealership if the swap was possible, he said that the 4.10's aren't offered on the 8" rear end, only in the 9.75" so just make sure it's possible to go to the 4.10's before you make a commitment.

------------------
'97 F150 4X4 Supercab XLT
Rhino Lining
285/75/16 BFG AT/KO
4.6L Triton V8
5 Speed Manual tranny

Coming soon:
K&N air filter
Superchip ( I think)

 

What? 4.10s are offered in the 8.8" rear end on the 4.6 truck. Someone is smoking crack at the ford dealer. Heck FRP even sells them.

Now for the front IFS diff, that may be a different story, but I have heard of IRS cobras with 4.10s. I dont know for sure up front.

 

What would happen if I went with the 4.56's. Would my get-up-n-go be faster or would there be no change. How much would it cost to get new gears put in and were could i get them done at.

[This message has been edited by JDm (edited 07-17-2000).]

 

I know 4.10s are definitely offered for the 8.8" differential. You will need a "reverse cut" aka "reverse rotation" R&P for the front.


------------------
1997 4x4 Expedition- 4.6L, true dual exhaust w/glass-packs, K&N air filter, SuperChip, airbox mods, Edelbrock shocks, 285/75R16 BFG ATs, 2000 "XLT" 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., tinted windows, Line-X bedliner, 285/60R16 Goodyear Eagle GT IIs and Prime #155 wheels.

http://members.visualcities.com/NoMo

 

4.56s will give you quicker acceleration than 4.10s or 3.73s or less. Yes it will feel like more power. It depends on the tires also. If you have 35" tires, than it will be like stock. If you have stock tires or like up to 285 (33" tall tires) than it will give you some more pickup. The only disadvantage is that on the highway your RPMS will be higher than before. So you may lose some MPG. Just find out what is right for you.

Cost and where? Call any transmission shop in your local area. Shop around and ask for referrals!!!

[This message has been edited by Matt90GT (edited 07-17-2000).]