i don't know much about gearing but i want to learn. is all i do know is that i have 3.55's and a turbo and i don't think that i have the towing power i should. I do live in montana and have a lot of 8% and steeper grades. on flat surfaces i have never had a load that i felt but any hill with the smallest trailer i seem to hit 1200 on my egt's and have to let off. maybe i have something wrong that i don't know about but i would like to figure it out. also for the record i run 285's, not sure how much that changes the gearing either

 

I found that hitiing second with the 3.55's put me at just bout 3200 at 60 with the c6 and stock size tires, also what kind of boost are you showing?

 

i run right at nine pounds with a banks sidewinder kit. I have a five speed and if i hit 3200 in second i am going between 35 and 40 mph.

 

wish I had the five speed

try droping a gear earlier and keeping it as close to 3k as you can get, might also adjust the wastegate for a bit more boost if you can witht he thin air up there

bottom line though 8% and a heavy trailer is gonna be a bit slow these ain't 400 hp trucks

 

if i try to hit 3000 i will melt down. I was pulling two atv's on a single axle tailer. (very light load) never had to down shift to hold 70 but had to let out cause the egt was so high. Maybe my gauge is wrong, but i wasn't going to test it.

 

(gearing.the lower the number,the higher the gear.4.10's are higher numerically than 3.55 of course,but 4.10's are lower gears.)

285/75/16 are 32.8" tall.
stock tires are 235/85/16 and are 31.7" tall.

this raises your gears to 3.43 (nothing drastic,but stock tires would take that 8% grade slightly better with slightly lower stock 3.55 gear.)

i went down in tire size,and lowered my gearing.im glad i did for the hills.i can tell i wouldn't care for 3.55 in many cases-id be in 2nd gear often where as now,i can plant it pre hill when loaded and maintain 3rd 1.1
i went lower to help ease loading my bed,but sure am pleased with the steeper gearing when i need it too.with the OD and my avg speeds of 45-55(65 interstate very rare) i couldn't be happier.
what do you run for a trans jyme?

location,truck use,trans,tires,gears,average speeds and knowing your engines powerband all require great planning to be happy or very unhappy with your rig.
i took a long time deciding on tire size.i made the correct choice for my application.but many people hate the looks of short skinny tires.myself included.but fuel economy,and proper engine rpm outweighed looks.i couldn't be happier.....until my dually conversion.

also, what is your exhaust setup?

 

info from banks say's if egt's get to high downshift
its towards the end of the owners manual
http://assets.bankspower.com/manuals...310-v3-web.pdf

basicaly if you downshift it can make the same power with more air flowing through and you should see lower egt's

 

I know that this is no comparison at all but my dads 05 cummins temp gauge does not move at all on the same hill with 12,000lbs. i figured my truck would be fine pulling 1500lbs. i didn't even have the pedal down all the way. i really think that there is something else wrong. i had to let out completely, grab 4th and just hold 50 to keep the egt's down to 1100. at this point i felt like i was idling. hardly touching the pedal

 

Jayme, turn your fuel down - sounds like whoever installed the turbo also turned the fuel up a bit too much, by turning it down you will lose some boost a the same engine speed but it will also lower your EGTs and allow you to revv higher (where the boost comes back up again)

 

I pulled a 20ft car hauler with a f-150 on it for 200 miles and never had this problem

 

You pulled that trailer with this same truck? So your EGTs issues came up all of sudden then?

 

I know this isn't y'alls area of expertise, but being a thread about gearing...

If i were to get an F150, 5.0L, E4OD (or is it AOD in 93?) and swap the rear axle to 3.08 gears, what could i expect for MPG?

 

16-18 mpg roughly.

 

Well, i was hoping for better, but it won't break me.

I'm used to being spoiled at 32-35mpg, but i want a/c and a bed.... Going to look at a 93 F150 in about an hour to replace my wore out Sentra...

 

yes that is correct the egt's just came up on a trip over memorial day weekend