This is my first post, I have been readign/searching forever. I love this site...

My truck came stock with 2005 Screw 5.4 4x4 auto 3.73 LS FX4 towing package and 255/70/17 tires. I'm putting 285/70/17's on and my research says 3.93 gears would put me back at stock gearing with this tire size. So 4.10's would be the next size to go to, Right?

I tow atvs and trailers often, so the stock gearing with a lil extra oomph would be perfect. I liked the power with the stock tires.

Does my math equal your math?

Thanks

Josh

 

thats probly about right, but from what i have read, going from 3.73 to 4.10 is not worth it. i would say 4.30's but they don't make a 4.30 for the front. remember if you regear you need to do front and rear to still be able to use 4wd, so 1500 bucks to go form 373 to 410 is not worth your time/money

 

Thats what I have heard too. I'd love to hear from someone who has done it.

 

If you are going to re-gear step up to 4.56's otherwise it is completely a waist of money. I am getting ready to re-gear mine. Check out this link for a lot of good info. First page is a walk through, however second covers alot of other good info.

https://www.f150online.com/forums/ar...p-rev-1-a.html

 

Man, but with 4.56 my highway mileage will suck! I will never go bigger than 33's and only pull 3-4 atvs. What would my rpm's be like with 3.73's running 75mph?

If I stay stock the tranny will run warmer and prolly wear faster
If I go 4.10 the truck would run a lil stronger than stock
4.56 would be a real puller but prolly kill my 65-75 driving, RIGHT?

4.56 just seem to be overkill!!!

 

there some way to calculate what your rpms will be but i am not sure. my rpms with my 315/70/17 about a 34.5 at 78mph its 2k rpm.

 

you should be fine running stock gears with 33's i wouldn't even bother with gears, IMO i wouldn't do gears until you step up to at least 35's

 

+1.

 

there's a place in san jose California called rear end specialties thay have bulit my crawler and my 1/4 miler if you find a place with a good rep thay can answer all your questions but do your home work ask around and find a good shop neer you and give them a call. but i think 410s are a wast of time.

 

I agree.

 

Yep....don't waste the money on it......the tranny will be fine with that setup. just get some headers or some other mod to make up for the lost power.

 

correct.

I would suggest, if you came into the shop asking about it, would be to look into upgrading your cooling systems vs. regearing. Your 3.73's are more then up to the task of pulling what you want with it. Staying below a 35" tires, I coudln't justify the money on the gear swap. And 4.56 gears are definately way overkill, unless you do plan to run 35" or bigger tires in the near future.

Look into a trans cooler with aux. fan attached. Helped pull air when your not moving, helps keep temps down. Something like this one:
http://www.troyerperformance.com/cgi...gno=PPI-ATCKIT

Then, maybe look into the Maghytech dif cover, and deep dish trans pan. These help keep my smaller 4.6 engine plenty cool. I tow a Samurai, as well as customer cars, and have the 3.73 gears and my truck does just fine. Temps are never an issue. I also use the Gryphon to monitor my temps, but you can pick up a Scanguage II for a fraction of the price, and it will allow you to keep an eye on your curcial temps. Better yet, go with the gryphon, you can monitor temps, plus get extra HP from Bill's custom tuning (power hungry performance). Your truck will be a completely different animal with custom tuning. He can custom tune one tune just for towing (you get three tunes).

Tuner:
http://dygytalworld.ehost-services139.com/php/

and dif/trans covers:
http://www.mag-hytec.com/

All those mods would be cheaper then the gear swap, and you'd benefit much more IMO.

 

Mercedes, thanks for the good post!

I have thought about other mods but did not think they would benefit as much as gears would. Would a programmer with 3 tunes, say 1 for towing. HP, and better MPG work okay with my truck with no other mods except for SIDO exhaust? A programmer sounds like a good thing to do.

But money issues aside, running 4.10's would be slightly better than stock gearing/trie size, correct.

 

Ya, a programmer would be the way to go, for your case, if you ask me. You need a little extra "umph" but don't need the expense of a gear swap. Make sure to look into a custom tuner, far more "bang for your buck". There is a section in this forum just for chips and programmers, thats where you can get lots of info on it. The big three are all equally good, from what I gather

vmp:
http://www.vmptuning.com/store/index.php?

Troyer:
http://www.troyerperformance.com/cgi-bin/ppistore.pl

and PHP:
http://dygytalworld.ehost-services139.com/php/

Reason I suggested PHP, was simply because the pod they give with the custom tunes, has an option to allow you to monitor 4 different gauges at the same time. I use it to watch accurate RPMS, average MPG, trans temp, and my cylinder head temps. My tunes are exactly like you said, one for best mpg, one for all out HP, and one for towing. I have no other power adders yet, as I have too many projects going ! ha ha But, with just the programmer, 35" tires, and no other mods (3.73 gears) my smaller 4.6 pulls just fine ! I tow some fairly heavy mercedes for our customers once in awhile, and no issues. I tow my Samurai to places that get damn steep and hard on the truck, never had an issue. Hope that gives ya a better idea.

 

Thanks again! I have read this forum over and over, but have skipped over the programmer section...

I got some more readin to do.

Right now I have a 2" lift, 33's, and 3.73's, so maybe a $500 tuner will be my best bet.