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Discussion Starter · #1 ·
Hello iam building a 1973 f250 lb with a lightly built 390 it’s got a Dana 44hd front and a dodge dually Dana 70 rear (not dually anymore) this is mainly a street truck to be honest with some light wheeling do you think I could run 40s on this rig if I take it easy on the skinny pedal it has a 4inch all spring lift crossover high steer no more Armstrong steering lol and it does have 4:10 gears and a 4spd manual
 

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Assuming you have power disc brakes in the front with the 8 lug bolt pattern, a NP-435, with 3.73 or 4.10 gears, the largest I would run would be LT285/75r/16s . I ran this on a Dana 44 HD (4x4 van) and had no problems buried to the hubs in mud sometimes. Though I did not run a locker, if I ran a locker, I would keep it to the LT265/75r/16s. You might want to check out the treadwright retread tires in the mud D pattern with the kwedge rubber. It does pretty well on and off road.

As for the gearing, HP, and torque and viewing it for a mostly street vehicle, on my 390 4x4 F-100 (I think 4.10s) with the NP-435, the sweet spot for the tires was 31s when towing, especially starting on a steep incline towing a car trailer. The FE is an awesome engine, probably one of the best built by Ford is the FT, but, not a lot of HP or torque stock and when you start getting to 33s it takes it out out of it's sweet spot for power.

FWIW: Ford never offered the 390 in a 4x4, 360 was it, though that is not to say a 390 was not swapped in. Many just have an air cleaner that says 390 swapped in.
 

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Discussion Starter · #8 ·
Assuming you have power disc brakes in the front with the 8 lug bolt pattern, a NP-435, with 3.73 or 4.10 gears, the largest I would run would be LT285/75r/16s . I ran this on a Dana 44 HD (4x4 van) and had no problems buried to the hubs in mud sometimes. Though I did not run a locker, if I ran a locker, I would keep it to the LT265/75r/16s. You might want to check out the treadwright retread tires in the mud D pattern with the kwedge rubber. It does pretty well on and off road.

As for the gearing, HP, and torque and viewing it for a mostly street vehicle, on my 390 4x4 F-100 (I think 4.10s) with the NP-435, the sweet spot for the tires was 31s when towing, especially starting on a steep incline towing a car trailer. The FE is an awesome engine, probably one of the best built by Ford is the FT, but, not a lot of HP or torque stock and when you start getting to 33s it takes it out out of it's sweet spot for power.

FWIW: Ford never offered the 390 in a 4x4, 360 was it, though that is not to say a 390 was not swapped in. Many just have an air cleaner that says 390 swapped in.
Thanks so much for the response and no it’s a donor from a 2wd I have measured the stroke
 

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I ran 40's Denman mudders on a CJ 428 1976 F250. D44 and D60. I can't tell you how many axles I broke before I sold it. The Ford F250 axle has an hour glass shape near the splines, right where it snapped every time.
 

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Discussion Starter · #10 ·
I ran 40's Denman mudders on a CJ 428 1976 F250. D44 and D60. I can't tell you how many axles I broke before I sold it. The Ford F250 axle has an hour glass shape near the splines, right where it snapped every time.
Do you think I would be alright with a 38 it is primarily a mall crawler I will have a off-roading rig separately from it it does have a dana44hd so I here that can help with the flex in the axle housing leading to less breakages but I don’t know how much
 

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Ran 35" power king tires needing the tall tire look. Looked good but were worthless. Got that out of my system, sold those and have stock tires. 35's were the worst thing on fuel economy. But IMHO if you're needing big tires for the look, it sounds like you have the axles setup to turn all that extra weight.
 

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Discussion Starter · #12 ·
Ran 35" power king tires needing the tall tire look. Looked good but were worthless. Got that out of my system, sold those and have stock tires. 35's were the worst thing on fuel economy. But IMHO if you're needing big tires for the look, it sounds like you have the axles setup to turn all that extra weight.
Yeah it’s just purely for looks I went with a 4inch lift should have went with a 2inch so 35s will be to small they will look like car tires lol and it legitimately is a mall crawler iam about to buy a 7.3 or Cummins for my light off-roading needs this truck is just to be loud and look decent while doing it lol
 

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YJ with '87 Vette L98 700R4 Atlas II Dynatrac 60s 4 link rear springs over front Mahaffey alum
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The TSL Thornbirds are available in sizes that will be ok for your d-44 . If its a street machine the Thornbirds will give it a trail machine look, even if its not. I think you can get a set of 4 for about $1300
 

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Discussion Starter · #15 ·
3124437[/ATTACH]member: 914669"]
Hello iam building a 1973 f250 lb with a lightly built 390 it’s got a Dana 44hd front and a dodge dually Dana 70 rear (not dually anymore) this is mainly a street truck to be honest with some light wheeling do you think I could run 40s on this rig if I take it easy on the skinny pedal it has a 4inch all spring lift crossover high steer no more Armstrong steering lol and it does have 4:10 gears and a 4spd manual
 

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YJ with '87 Vette L98 700R4 Atlas II Dynatrac 60s 4 link rear springs over front Mahaffey alum
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Yeah I was looking at tsl or nitto I haven’t decided yet
I have TSL 44 boggers. If they ever wear out I'd buy TSL again. For a big mud tire they are well balanced right out of the box no shimmy or shake. Nitto looks like a very nice product but IMO a bit overpriced.
 
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