New Ford 7.3 gas with 3.55 / 3.73 rear end

[Dale Moser]

You guys who have bought the 7.3, order some extra spark plub wires to keep with you. I have a good friend with one and it layed down on him outside Corpus the other day, the codes say misfires on 2 cylinders, and they have determined the plug wires are failing under heavy use. I'm sure they will come up with a better one, but his truck has been 400 miles away for over a week, and they say they can't get any more until early October. Just something to think about.

[TX03RUBI]

You guys who have bought the 7.3, order some extra spark plub wires to keep with you. I have a good friend with one and it layed down on him outside Corpus the other day, the codes say misfires on 2 cylinders, and they have determined the plug wires are failing under heavy use. I'm sure they will come up with a better one, but his truck has been 400 miles away for over a week, and they say they can't get any more until early October. Just something to think about.

That’s the video Scott just posted above you. Seems to be a common thing with it.

[RMW]

18k behind the truck. Yep I realize that would work the truck pretty good. Not much of an issue if it’ll handle it though. Most of the time I’m only driving 15-20 miles with it, and my long trips are 10K or less.

Buddy pulled my 36ft gooseneck trailer with tractor and shredder to the lease about 120 miles a few weeks ago and it did really well I was surprised. Gas mileage was about 6-7 mpg though. Got up to 75mph with no problems.

Trailer weighs around 7,000lb
Tractor John Deere 120hp weighs 9,000lb
14ft rino shredder weighs 3000-4000lb

Here is trailer and tractor that he pulled, picture was taken last year on different truck.

[muzzlebrake]

There are two things a man will lie about.
1. the size of the fish he caught
2. the gas mileage his truck gets

[KactusKiller]

OK here goes.

Made a trip from Rogers TX to our deer lease between Rotan and Jayton with a 16' trailer loaded with 4000# of corn and other accessories for cleaning/mowing our camp along with a 2015 Artic Cat in the back of my F350 C/C Long Bed STX/ FX4 4x4 with Ford's new 7.3 gas engine and 3.73 gearing.

To say the least this thing is a beast. Put it in Tow/Haul mode and it never faltered. Down shifting was not a problem and there were times I looked and it showed me doing 80 with times at 85. MPG, no idea as I did not buy this truck for gas mileage period. You want gas mileage buy a Prius. Probably 9 to 10 mpg, but I do not care.

This truck never faltered on any hills and there are some good descent and climbs along Hwy 36!

Would I recommend this set up to anyone HECK YES! It will get up and go and haul *** when needed!

The more miles mine has got the better it runs. Up to 2k now. I wish mine had the 373 instead of the 355. I think it makes a huge difference with a gasser.

[BETTERLUCKYTHANGOOD]

I just got back from a trip to New Mexico and Colorado pulling an 18' enclosed trailer with to HDs, our riding gear, food, drinks and misc stuff....total weight of the trailer and gear was about 5500 lbs. Ran steady at 75-80 mph. 2020 7.3 CC 4x4 standard bed 3:55 gears. Mileage was 11.1 - 12.2 hand calculated. Love the truck and power, but I will be installing the 3:73 gears in it. Personally I think the whole package would work together better with the 3:73 or 4:30 gears (if towing real heavy). When I bought the truck the only ones I could find had the 3:55 gears. The truck now has 3650 miles on it and has less than 200 miles that it didn"t have a trailer hooked to it. Still waiting to break it in.

[Tex1986]

I really would like to hear someone’s thoughts on this truck with 4.30 gears and some heavy weight. Like 15K+. I usually weigh in the 15-18K department depending on which trailer I grab.

I personally dont have a report however a good friend of mine has a 7.3 gas F350 DRW with 4.30 gears and pulls a 16k toy hauler regularly amongst other items in the 5k to 8k range multiple times a week. He says with the toy hauler its running 70 mph in 7th gear running about 3,000 rpm's.
He says it does use more fuel pulling the toy hauler than his diesel did. On the lighter trailers and running around town hes says his 2019 cummins and the new ford have about the same mpg.
The new ford is sitting on 35's.
The 2019 cummins 3500 had 37's.

[KactusKiller]

I just put 35” toyo RT on mine.

[Rubi513]

I just got back from a trip to New Mexico and Colorado pulling an 18' enclosed trailer with to HDs, our riding gear, food, drinks and misc stuff....total weight of the trailer and gear was about 5500 lbs. Ran steady at 75-80 mph. 2020 7.3 CC 4x4 standard bed 3:55 gears. Mileage was 11.1 - 12.2 hand calculated. Love the truck and power, but I will be installing the 3:73 gears in it. Personally I think the whole package would work together better with the 3:73 or 4:30 gears (if towing real heavy). When I bought the truck the only ones I could find had the 3:55 gears. The truck now has 3650 miles on it and has less than 200 miles that it didn"t have a trailer hooked to it. Still waiting to break it in.

I wouldn’t think there would be enough noticeable difference going from 3.55 to 3.73.
You could go with just a little smaller tire and get the same results.
If I was spending the money for a regear, I would go 4.30...

[BETTERLUCKYTHANGOOD]

I wouldn’t think there would be enough noticeable difference going from 3.55 to 3.73.
You could go with just a little smaller tire and get the same results.
If I was spending the money for a regear, I would go 4.30...

Trust me I have been thinking about that also. Seeing how I only have less than 4000 miles on the truck and really haven't driven it empty much yet, I still have time to figure things out. Won't be a lot out of pocket for the gear change, I'll do it myself, it's what I do for a living.
I don't expect to be towing more than 8-9,000 lbs, I have seen a video that the guy was complaining that with the 4:30 gears 1st and 2nd were useless when not towing.....but then that is what the 10 speed trans is for along with 3 overdrives.
Still in the discovery mode as to what I will MOD on the truck.