I am building a truck to run at local mud boggs. I currently have a light trail rig . 71' f100 360 CI engine/np435 trans/ dana 21 tcase /dana 44 front/ford 9" in rear. I am going to purchase a 79' F350 for 300 bucks.It has dana 60's front and rear/c6 trans/np205 tcase/460 ci. engine. I want to put this stuff in my truck.I had the frame powder coated. I am planning on running 44"boggers. My question is how hard will it be to put the one ton stuff under my half ton. And what gear ratio should I run ? Any help greatly appreciated.

 

I think it would be easier to put the body on the 79 frame, The frame on the 71 is narrower than the 79. It would take a lot of fabricating to put all the pieces on the 71 frame.

To be effective with 44" tires you will need at least 300hp out of your engine and low gears like 5:13 or lower.

I run in competition mudbogs and run the 44" tire class, with my 40" tires. I am very competative in that class because most people buy great big tires and just dont have the poop to turn them. They look cool but if you cant spin them .......you will just look silly.

 

Yup, you are going to have to gear the heck out of your rig to run 44s on that 360 unless you dump some dough into the engine. I would say 300hp is conservative. If you want to be competitive I would knock it into the 400-500 hp range. Tellico gave good advice...power vs tire size is more important that just having gumbo tires.

 

If your racing it, you would be way better off with 38x11.50's..

I would just turn the F-350 into a mud truck, and leave the 71' for a normal truck.

 

throw a 4 inch lift on the 350, put the 44's on, go to town with the airnibblers or sawzall...or wutever ya want. then sink about 2-3 grand into a 400 plu.s hp 460. Run some 5.13's and weld the rear and violla

if ya toast the rear 30 spline 60, find ya a sterling 10.25 and she'll blot right in.

 

a few things to keep in mind when building a mudder, especially one with 44's......
1)5.13 gear ratio would be perfect for spinning those meats, but have you ever played with 5.13's before? they suck...the pinion gear is the size of my pinky, and with 33's it goes snap crackle POP. i run a 3.50 ratio, and the pinion is huge, a downfall to that it my driveshafts need to be BEEFY, but they should be anyway in my opinion.
2)for around $500 you can get wide ratio guts for your c-6, wich i have done three of and it is the BEST ever. first gear is nice and low, second is right there in the middle, and third is the stock 1:1 ratio so you can still get up to 65 on the highway. also with the lower first and second in the tranny, you can run a taller axle ratio that has some more meat to it and can handle the amount of torque+tire you want to run.
3)if you do run the c-6, throw a big cooler on it, she will cook when you are playing in the mud, this unfortunatly i know from back when i was a kid with my very first c-6
4)in the axles...with 44's lockers are a MUST, and you might want to run a slightly taller (around .1 differance) ratio in the front. i have found that this helps in keeping your truck going where you point the wheels, not where it feels like going off too.
5)the more gut busting power you can scavenge from that motor, the better....specially with 44's.
6)this is just my opinion, but i have seen 44's reek havoc on many axles, among them a 10.25 and a 70.....i would recomend something in the 38-35" range. this is just my opinion, but id rather get stuck rather then spend every sunday fixing saturdays broken axles.....food for though i guess!

 

"4)in the axles...with 44's lockers are a MUST, and you might want to run a slightly taller (around .1 differance) ratio in the front. i have found that this helps in keeping your truck going where you point the wheels, not where it feels like going off too.
5)the more gut busting power you can scavenge from that motor, the better....specially with 44's. "

With that said do not go over 3% with yer ratio, dont wanna blow yer T-case. I run 4:88s in the front w/ 4:86s in the rear.
Lockers.....run a full spool in the rear and a detroit in the front, works well for me. Also buy yerself some CTM joints and some warn shafts for the front. Lifetime warrenty on both but if ya break an axel dont tellm yer runnin CTMs they will void the warrenty.

 

yes, 3% would be a better number to go with, i said .1 of a differance, but then again our mud runner doesnt see ANYTHING but mud when in 4x4, and if we were to hit some ground with some traction while still in 4x4, the tcase would pop, and it has before because we forgot one time. i wasnt thinking too much when i said that, sorry. let me tell you though, the .1 differance we run KICKS *** in the mud, she goes straighter than straight and turns like the devil when we want her to!

 

with that big a motor you shouldnt need much more than 4:88s, also they will give the rest of your drive train more life. The problem whith 5:13s is that the ring gear gets too big and almost isnt worht it, putting a bunch of torque through 5:13s breaks ring gears realy fast (i have seen it happen many times). All the ud guys i know run a .1 variation too and it works realy well. But the most important thing on a mud truck is a tow strap rated at atleast double your trucks wieght.

 

My mudtruck has a d44 and a 9" with 5:13 gears and they have been working good for me. I am running 39.5" boggers on the back, 40 " gumbo's on the front, and a 429. I got a full spool in the front diff too

 

the next time you find an f350 with d60 front and rear for 300 greenies, email me.