SCORE!!! Dana 44 out of a 77 F150!!!

[fordman]

my 4wd has 3.50 front and back. and the truck seems to not go much over 55 miles an hour. have you checked fordification.net for the proper 77 axle diagrams. they may not be loaded yet. or you may be able to see something in the diagrams on this site.

[Doug F]

Yes sir, I posted here and there, I agree that it just might not be up yet.

I would check the carb and ignition if you aren't getting much more than 55 mph... My new truck has 3.55s in it and 31" tires and has been over 110 mph and gets 20 mpg!

[fordman]

well right now the enigne runs like garbage but it does run. so that could be my first problem and it probably is from what i know about the engine problems. its part carb and part used timing chain i put back on it. however before i got the truck it had a different engine in it that ran fine. and ezernutt drove the truck with the good engine in it. and he reported the same highway speeds. anyway that is what chris and i both expereince with this truck. when i get the engine fixed this fall i will know for sure how fast it will drive for sure.

[AK F100]

With running 3.50 gears, 32" tires, at 65MPH, you'll be turning 2389 RPM's in 4th gear. (33" tires would be 2316 RPM's)

With running 3.70 gears, 32" tires, at 65MPH, you'll be turning 2525 RPM's in 4th gear. (33" tires would be 2449 RPM's)

[Doug F]

I am trying to get an idea as to what other's experience is with such combos.

What I have to compare it to is my Mustang's cam pulled HARD from 2000 to 6500 and it was at 2000 at 55 mph, so it was perfect for highway... It was a high revving 289.

The 352 motor is a bit harder to rev and with max torque at ~2400 rpm and max HP at about 4200, wouldn't I want to use the 3.50 to give me more pull for climbing hills and passing?

My understanding is that with 3.70 gearing, I will be on the backside of the torque curve and loose that "oomph" to pass and maintain cruise in the hills.

I am just working on my own theory and am open to corrections and suggestions.

Thanks!

[AK F100]

I agree, it's hard to tell without someone else's real world experience.
I was just crunching numbers.

[Doug Comer]

For what its worth, I had a 68 Chevy with 3.73 gears and a very mild 350 and ran 32" tires. Of all the trucks Iv'e had I always liked it the best. Took first place at the local truck pulls and I could drive it 65-70 if needed.
Doug

[Doug F]

Thanks AK and Doug... I appreciate the input!

Since the front axle is already out and apart, I am thinking more about doing the 3.73 thing, but at the same time I want to get a 77 rear 9" too, so I can run disc brakes out back as well, and will then probably look for a 3.50 rear. I guess there isn't really much difference between these 2 ratios... It's not like 3.5 vs 4.11

I wish I knew more and since Doug is the only one so far with actual input, I will wait and hope someone else has some to help those of us that don't. That's why

[binder56jd]

1st of all--great paint work

this is all ihc experience--scouts and travelalls--same dana setups---all running 31-10.50-15's--this size of tire will effectively change a 3.73 to a 3.54

on both scout and t'all 3.73 with 31's highway mileage 15 +/- depending on load and wind---345 and/or 392--4 bbl--ac--auto


scout with 345 2bbl 3.08 and 31's----hiway 20 mpg +/-

all setups still had plenty of grunt for normal 4wd offroading

if u intend to run bigger than 31's--stay with the 3.73 or u may be disappointed in acceleration

enjoy the ride

[binder56jd]

http://www.tellico4x4.com/moreinfo/ratio.htm

[Doug F]

Thanks man, I have gone through many of those charts and most are different for some reason, but like you said, bigger than 31s stay with the 3.70. I am hunting for a 3.73R ring and pinion for my D44, among other things to make it all come together.

I also appreciated the real world MPG info, stuff like that is helpful too! My truck supposedly weighs 4020lbs, which is pretty light compared to vehicles today. My old 67 Mustang weighed 2300lbs all stripped out and that got 12mpg! But it was NEVER driven easy!

Thanks again!

[greentruck]

I have a 390 2bbl, np435 and still have the 3.50 gears while running 35s. Even with the granny low, I lack the ability to crawl or torque over/through certian obstacles on the trail. I top out around 75 mph and lose any ability to pass or accelerate after 60 mph. I get around 12 mpg.

For what it is worth I would like to change my truck to 4.11 or 4.56s, so if I had to pick between 3.50 or 3.73, i would go 3.73

[jeepermc]

Since the front axle is already out and apart, I am thinking more about doing the 3.73 thing, but at the same time I want to get a 77 rear 9" too, so I can run disc brakes out back as well, and will then probably look for a 3.50 rear.

I'd go 3.73 if you can....

Am I missing something with the rear disc brake thing? You say Explorer discs but the wheel bolt pattern on an explorer is 5 on 4.5 where these trucks are 5 on 5.5...

[Doug F]

The discs need to be modified, the center hole made bigger or the axle "hub" turned down and then re-drilled for 5 on 5.5. It's a common swap these days... I think Currie or someone already make custom discs to ease the install.