I have a 2005 STX w/4.6L and I believe 3.55 gear. I have been towing a boat this summer and it's been handling it OK except for a few big hills which it seems like it just loses total power. I will be towing this boat quite a bit so I wanted to do some upgrades to my gears. I also installed a 2" AS and 33" tires a while ago. What do you guys suggest I do? I'm thinking upgrade to a 4.10.

 

The gears will help but putting larger tires on did not.

 

if you do more towing then just driving at highspeeds on the highway, 4.56 might be better for you

 

Either change your tires back to light weight (p load rating) or get 4.56 gears.

 

I would suggest the 4.56s. The 4.10s are still too small for your needs.

 

Alright but will the 4.56 have a bad effect while I am not hauling?

 

You may notice MORE torque, and they may limit your top speed. But that is about it.

 

All F-150s are limited to 98mph, so top speed is not affects. You'll just get there quicker.

More engine speed can mean more fuel used, but with 33" tires, you'll probably increase FE as well.

 

Assuming you are 2wd you could also go with 4.30's. Those would be a noticeable upgrade over your 3.55's and not be so steep for highway driving if that's your concern.

Hook'em!!!

 

Unless you have "tweeked" it, and in my case it is now 120 mph.

 

I put 456's on my 02 5.4 4x4 with 33's. I towed with it and what a difference on climbing. I towed a 99 Navigator recently.Total of 13340 lbs in weight according to roadside scales used at truck inspection station. Around town not a problem. I set me top speed limiter to 128 and it still gets over 100.

Best move I did.

I plow also with this.

 

alright, thanks for all the feed back. I think I will go with the 456's as long as that isn't going to do any damage to the truck in the long run. If anyone has any bad experiences with this let me know. Thanks again.

 

Glad I saw this thread. I also have a 2004 STX with 4.6/8 triton and want to upgarde gears due to purchase of new camper..... I also have a leveling kit and 33" tires so I know that isnt helping matters

Glad I found this thread...... Any Idea on Price??

Does anyone know what something like this would run at a transmission shop???

 

4wheelparts quoted me $1030 for 4.10 gears with limited slip (locker?) installed.

 

Thats a good price for both front and rear gears installed.