Heres what I want to do to my D100. I want to pull my gooseneck trailer with it. dana 60 rear beefed up springs are the simple steps. I want 8 lug all the way around. What I'm having trouble finding is spindle measurements. In my research the D250 and and D100 use the same brake caliper and pads and the same bearings. But the 250 rotors are just a tad more than 1 in. larger in diameter. Will it work or are the spindles diferant sizes to comp. for the larger rotor?

 

there is no point in installing a dana 60 or 8 lug rotors on a d100. it is just a d100 which is legally a light 1/2 tonne truck. you are better off just leaving the stock axle and rotors on it and just upgrade leaf springs and coils. the axle should be able to put up with all you are allowed to legally haul.

 

With the suspension and axle swap it will be a 250 in 100 cloths or a wolf in sheep cloths.

 

just get a full size 250 or 350. i had a ram 1982 HEAVY DUTY 250 it had 1 ton brakes. and was rated for duel rear tires. so double check these things. that year the 250 came in 3 different load ratings. i cant remember them now. just check the load ratings on the factory label. a factory service manual will have all the info you need.

 

every thing is larger on a 3/4 ton than 1/2 ton

 

sounds like you want to waste money. if a b250 can survive with 5 lug axels i don't see any reason a d100 would be any different. i have hauled 3000lbs in the box of my 81 on a couple occasions and the axles are just fine.

 

Nothing you do will ever make it legally able to haul more. As has been said, lots of things are different: control arms, bushings, springs, master cylinder, 6" vs 7.5" frame, etc. I'm sure there are other differences I'm forgetting as well.

I suggest doing a body swap onto a d250 chassis using the d250 vin and all possible components.

If I recall, the various load ratings of d250 use different size bearings, and I believe the spindles likely have various diameters.

How heavy is your trailer? Is it a livestock trailer? Utility trailer? I can probably give you an idea on what your problem areas are going to be depending on the weight of the trailer.

 

Thanks for a reasonable answer. Its a 20' gooseneck weighs 2500 with brakes on all 4 wheels so stopping is should not be a issue. I mostly use it to haul my jeep weighing 3500 and my 35 horse tractor with a front loader and brush hog.

 

That doesn't seem like too much. It might be over the legal limit, but not by much. I'd suggest helper springs for the back obviously, as that will be a lot of tongue weight for a d100. And of course a transmission cooler. What gears does your truck have? Hopefully the transmission is a 727. A 904 will probably not like that.

 

I forgot to mention, make sure your tires are up to the task as well, and aired up a lot. I wouldn't want to put a lot of tongue weight on itty bitty tires like the 235/75/15s on my ranger.