Swapping front axle 1968 Ford N950

I've got an old truck that's heavy duty double frame and the whole works. The problem is it only has an 11000 pound front axle and I would like to swap it. All that I have seen seems to indicate it's all about Center to Center spring centers. I don't remember off hand what that actual measurement is but I have quite a few other trucks and nothing matches that. Is that width a manufacturer thing or is that a model thing? If I can find the same Center to Center is it just unbolting and bolting up the new one? I'm not worried about the steering box because I can fabricate or have someone else fabricate me the linkage. I am not sure about double steering boxes though. Seems like that would be more difficult. I am looking for 12 to 16 thousand pound front axle. I don't remember the spring width (each spring) offhand but it is the same as another truck I have that has a 16000 pound front axle.

Also I think all truck frames are 34 inch wide. Can I take one of my parts trucks and just take the whole front axle Springs and hangers and put it on that one?

 

Thanks for the quick replies. That's good to know that Kenworth remained the same. The truck is a 1968 Ford N950. I would have to check the L model Fords, as they replaced the N model.

The problem that I am seeing with any of this is that the front end is so short that I can not use the original linkage from the (single or) Dual boxes to the axle.

If I did use a heavy axle with dual steering boxes, I'm thinking that someone coulld fabricate me an adjustable linkage similar to how a tie rod adjusts. is there any kind of special procedure for setting up/ synchronizing those dual boxes or do you just put them on like a single box?

 

Thx fuller. That was a good part of my concern.

We'll have to see what kind of situation I can find to put under there.

 

The axle that has the right spring center to spring center would be easiest. I could just swap the axle then. I have not measured shackle to shackle (frame width- which I think is almost universal), but all of my other trucks and spring/axle sets have longer springs, which would require drilling and centering.

Someone else mentioned power assist also. How does that work and where would I find such a thing? I have an f800 dump truck that has a cylinder for power assist that attaches to the axle itself. Is it something like that?