Bowtiesr4me (Mike),
For the later-model integral PS steering box (cross-steering) type kit solution (similar to kit used by bowtie70ss) have a look at:
http://www.classictruckshop.com/t1_page4.asp For the N.O.S. (duplication of original GM linkage power steering) kit solution, have a look at:
http://www.classicperform.com/power1.html Unfortunately, this kit costs like the devil.
Or, you can fab up your own set-up as I did. I realize that things I find interesting can be scary to others, but then I’m used to engineering innovation. If that isn’t your cup of tea, then I suggest you stick to somebody’s engineered (and tested) kit. Briefly, let’s talk about using a rebuilt later-model PS box, but in drag-link (not cross-steering) mode. First, you need to determine which way the pitman-arm and drag-link move when the steering wheel is turned clockwise (right turn). If it’s like mine, the pitman arm rotates counter-clockwise thus moving the drag-link rearward for a right turn. When the steering wheel turns clockwise but the pitman arm rotates counter-clockwise, this is known as ‘reverse-rotation.’ Most of the PS boxes you’ll find are ‘standard-rotation’ but exceptions do exist. I found that the ’78 Dodge trucks used both standard and reverse rotation PS boxes (and the reverse-rotation boxes seem to have very low core charges for some reason).
A later-model PS box will usually have to be turned 90 degrees in order to have the pitman arm in the horizontal plane, as with a stock steering box. This means fabbing up a bracket of some sort to accept the new PS box’s bolt-holes. Yeah, it can be a pain-in-the-butt – and you have to go with a later-model steering column and a rag-joint (another pain-in-the-butt). I have seen on E-Bay brackets to adapt a Toyota PS box to a frame-rail for drag-link steering. You might want to check that out.
I ordered the cross-steering PS kit from Chevy Duty, but sent it back after considering all that has to be done and how it affects the steering geometry. I prefer to stick with drag-link geometry for a solid axle. I’m not saying not to use this kit – just be careful if you do and follow the directions explicitly. The remaining choice is to fab up your own original type GM Saginaw mid-50s ‘linkage’ power steering system as I did using C-2 or C-3 Corvette components. I like it because I don’t have to install a new steering box or steering column, nor do I have to change the steering geometry – it’s still a drag-link system just like the original GM design . . . but it’s still a pain-in-the-butt.
Now (foolishly perhaps) I’m going to comment on welding of steering components. Having read all the epithets and put-downs from the ‘shortened steering column’ thread, I really don’t need to hear all the ranting on the subject of welded components. Frankly, these guys screaming about the evils of welding sound to me like a bunch of little old ladies decrying the evils of smokin’ and drinkin’. If we could get past who’s the greatest welder on the continent, I’d like to offer a few comments on the subject as applies to pitman arms (I’ll have to use some of the engineer talk that nobody likes, so please excuse me). Structurally speaking, a pitman arm is a cantilevered beam subject to a point load. The formula for the bending load on a cantilvered bending load is ‘PxL.’ Divide the bending load by the bending allowable (for mild steel you can use 22 ksi) to get the required Section Modulus (a structural quality that measures resistance to bending). Cutting to the chase, if you do the math you’ll find that the Section Modulus requirements for a pitman arm are relatively low, particularly if power steering is employed. A really good weld, helped out by the arm being sandwiched between a couple of steel plates welded on, will deliver a Section Modulus many times the requirement. And, yes, Magnafluxing and stress-relieving are always wise. One more thing – never splice two pitman arms together using a straight cut. This allows shear stresses to accumulate along the straight weld-line under torque. Using male and female ‘Vs’ cut into the meeting places of the two pitman arms will keep shear forces from bearing on the entire length of the weld-line.
Sorry for being so verbose, but I hope this helps you in making a choice. Know what you’re doing and use qualified people, and you should be alright. If you don’t know what you’re doing, please don’t take any chances with your own safety or the safety of others sharing the road – use an engineered kit . . . or stick with the stock steering. You'll have Pop-Eye arms in no time.
Regards,
Apache