Not sure if my last post actually posted so I'll try again.
Is there a particular make and/or model of weight dist. Hitch, trans. cooler, and ring & pinion that I should consider? I'm assuming some are better than other?

 

As for WD hitches, I prefer the Reese Dual Cam Sway control system

 

I can't recommend a hitch because mine was a hand-me-down from my dad.

My 4.30 gears put my RPM at about 2,300 at 65MPH with 34" tires, so with 35" tires you will be slightly lower.

I think the tow/haul on your tuner probably changes shift points in the transmission. You probably only need O/D on when on flat ground regardless of the tuner setting.

I don't know how your trailer is laid out, but if the water tanks are up front you can keep them empty when towing to lessen the weight up front.

 

I'll bet the 5th wheel rails were from before the lift.

If you aren't attached to the lift and big tires, I guarantee you would find many takers to swap them for stock sized gear. Also, if the dollars aren't there for a re-gear, keep an eye on craigslist or the boneyards for used axles with the shorter gears. Both 4.10 and 4.30 were factory set ups.

The lift might be adding to the low tongue weight if the hitch isn't low enough.

 

I'm sure I would be closer to divorce than a fix to my situation if I get rid of the lift and tires. My wife just replaced the tires a couple months ago for my birthday.! As far as the 5th wheel...the lift and 35" tires actually were on it while it was used to tow the trailer. I can afford the gearing and airbags, WD hitch and the small stuff. It's changing the appearance and big ticket items that are out of the question. As far as current gearing I was under the impression the 373's were factory gearing for my truck. At least that's what the ford factory tag says on the pumpkin. Now whether or not those are what are actually inside is anybodys guess. At about 65-70 mph I am somewhere around 1900-2000 rpm. Anything over 2000 rpm my mileage really begins to suffer!
BTW...you guys are very helpfull. I am currently trying to price all my new toys. I just want to make sure on the gears before I make the purchase. Should I be running the 486's or something different?

 

Sorry....typo. Should I actually be running the 4:56's?

 

JMO and I have a lot of experience towing with the SuperDuty V-10. Lose the lift and the big tires and return it to stock. Rear gear is not ideal for towing, you need to switch to a minimum 4.10 but a 4.30 would be better. Buy a quality WD hitch that has integrated sway control. I use the Reese HP Dual Cam and have good success with it. The Equalizer brand is also acceptable.

 

Not to beat a dead horse but again, I'm trying to get help for my current application. I cannot change what I have currently as far as tire size and lift. Right now I asking for help choosing the right fix (or at least as close to the right condition) for what I have which is keeping the lift and the 35" tires. Thanks for the input though. I truly understand what should be done optimally, but I really need to work with what I have. I really like the look of my truck and again, it's not an everyday driver or every weekend tow vehicle.
Thanks again...

 

Your truck probably has 3.73's if you are at 2,000 RPM at 65 MPH with 35's.

Your MPG dropping when over 2,000 RPM is because you need more throttle to maintain higher speeds with the 3.73 gears. This is even worse when running bigger tires and towing that tall/heavy trailer. That is why 4.30 gears are better for the V10 and will give you better MPG and power.

When calculating your MPG are you factoring in the 35" tires? If not, you need to add about 6% to your calculated MPG (10 MPG X 1.06= 10.6 MPG). You can find some calculators here to figure out the difference in tire diameter/speedo.

 

The 7.3 guys like to use the trans coolers of the 6.0's cause they're bigger then our factory ones. Not sure how they compare to the gassers though. I remember Mark K saying that you want to get whats called a "stacked" cooler. Its more efficient then simple tube and fin coolers, and is less restrictive, which means less extra work for the trans pump.

 

Thank you. I will check out more info on the cooler! As far as MPG, I understand I'm gonna take a huge hit on mileage while towing! I've never not factored in the mileage without the tires cause they've been on the truck since I bought it! Mileage isn't too much of a concern as again it's not a daily driver. Just want to make sure I stuff the correct gearing in and it not be so much of a "crap shoot"!
Thanks again.

 

Oh and not sure if this helps but I have a stock trans temp guage. Whether I'm towing or not the needle always climbs to the middle of the gear and never moves!

 

leaving the tires on, you need to change gears..to 4:30 or 4:56….
dual cam hitch, with 1,000-1,200 lbs rated head and bars..… adjust the head so the bars aim down a bit. 5-7 links between bar and hook. set the dual cam placement and tighten with the dual cams in the notches.
max brake controller and hitch height set about 1" low... measure height at top of ball, with both rigs level and unhooked….
stay under 65 mph if using trailer service tires…
let the engine run, not gonna hurt it at 45-4600 rpm for half hour or so..
big transmission oil cooler, largest that you can fit… you can't over cool the transmission unless you live in the great white north…
max out the trailer tire air pressure, as posted on the sidewalls..
adjust the trucks air pressure to whats recommended on the door jam for stock sized tires, with your tires, look at the sidewalls. take em up to about 10 psi less than the sidewall max. and see how they wear and feel….
check the tire temp to see if your getting the same heat across the tire.. low tires are squirrelly and will wear the outsides of the tread... over inflated tires will wear the centers out..

 

Drop down to the modular v10 forum. There is a lot of good v10 info there with experienced folk.

I have 4.30 gears but don't tow very often, my truck hauls more often than tows. Most recommendations i have seen for set ups like yours say to go 4.56 . Given that the truck isn't a daily driver, you won't mind those gears at all.

 

If money is your main concern (and not maintaining marital bliss ) you might want to reconsider your aversion to removing the tires and lift. Considering your truck is 4x4 you could probably sell the current setup (or swap someone straight across) and go back to stock for less than what it would cost you to regear both axles.