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I have a 1994 f-250 with a 7.3L diesel . I was told it has 4:11 gears .It has a 5 speed manual trany and a top speed of 60 mph at 2000 rpm . Would like to keep lower gears for towing but more speed for highway . Was wondering if somebody makes a 6 speed trany. Any suggestions
 

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People have swapped in a ZF-6 but I don't think the overdrive ratios are much different. The best case and easier would be an overdrive unit. I personally have a dually F-350 and just swapped in 3.55 rear end gears instead. I only tow about 8-9k lbs and it handles the flat lands just fine.

OD unit below.
https://www.gearvendors.com/
 

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A 6 speed transmission isn't going to get you anything other than a extra gear to shift into. The final drives are close to identical to the 5 speed.

Your only choices are either a gear vendors over drive or going to higher rear end gears.
 

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He's probably trying to get mileage. I can get 20.7 at 55 mph on flat ground running empty with the cruise on. I ran at 72-75 one time and was only getting 12 mpg.
 

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He's probably trying to get mileage. I can get 20.7 at 55 mph on flat ground running empty with the cruise on. I ran at 72-75 one time and was only getting 12 mpg.
It also depends on how he is running. Last week I took a trip at constant freeway speeds of 75-80mph and got just over 20mph with my truck and 4:10's in the rear. The same trip a couple of weeks ago with 1000 lbs in the bed and I got 17mpg.
 

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It also depends on how he is running. Last week I took a trip at constant freeway speeds of 75-80mph and got just over 20mph with my truck and 4:10's in the rear. The same trip a couple of weeks ago with 1000 lbs in the bed and I got 17mpg.
sorry but no way are you getting 20+ at 75-80mph with 4:10 gears, unless you were coasting downhill the whole way :lol:
 

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sorry but no way are you getting 20+ at 75-80mph with 4:10 gears, unless you were coasting downhill the whole way :lol:

You want to make a wager on that? I have gotten as high as 22mpg all freeway driving at 75-80 on a trip to Canada a few years ago running on both tanks.
 

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I'm a bit skeptical myself. I've gotten over 23 mpg with a 5.9 Dodge but it had 3.55 gears. My Ford has never seen 22 mpg no matter what. What kind of mileage do you get at 55? 30 mpg?
 

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I'm a bit skeptical myself. I've gotten over 23 mpg with a 5.9 Dodge but it had 3.55 gears. My Ford has never seen 22 mpg no matter what. What kind of mileage do you get at 55? 30 mpg?
Who drives 55? 99% of my driving is all freeway at higher speeds. When I throw in some city driving I'm at 17-18mpg until the winter fuel hits and then I'm right at 16 for most of the miles and that is when I haul the most weight.

It was interesting a couple of weeks ago my nephew was driving his 97 cclb with about the same weight that I had in the back of mine and he used 4 more gallons of fuel than I did on the same point to point trip. He also mentioned after riding in my truck that it seamed like it was lower geared than his but I do have a few mods on mine that he doesn't have on his. So I have a little bit more HP

Perhaps it is my driving style or perhaps I just got one of those engines that works the way that it is suppose to, I don't know but I'm keeping my truck for a few more years.
 

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I ordered my truck with 3.55 gears, when it was my daily driver to the tune of 32,000-33,000 miles/year I'd get 18-1/2 to 19 mpg in summer running 70-72 mpg, about 2200 rpm. When I replaced the factory 235R85-16 tires with 255R85-16's I bumped mpg about 4-5%. I averaged 20 mpg to 20.5 mpg all summer, 10,000 miles. Lots of drafting semi's, coasting down hill, etc. In order to get that mpg. Really hot days when I ran A/C I got better mpg than cooler days with the windows open.
In winter I'd lose about 8-10% because of cold tires & oils pulling harder, winterized fuel, more windy days. Don't laugh about the cold tires pulling hard. Back when I drove semi I pulled several trailers a day. You hook up to a cold trailer with a warm tractor that's run 150-200 miles and it takes 20-30 miles for tires & wheel bearings to warm up so you can roll again.

Anyhow, 3.55 gears are fine unless you tow over 7000-8000# a lot. I've pulled 10,000# and even in hills my stock 7.3 did just fine
 

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Dr. Evil, did you recalibrate your speedometer after you changed to oversized tires?
 

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Gears are going to run you around $1000 a axle if you have someone do it for you X 2 if it is a 4x4 that is a lot of diesel to make up. And it really isn't a job for a person that isn't experienced in it.
 
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