Actually, the only time I've ever seen a steering column fail on the road was due to a broken rag joint on a Ford PU. A friend of mine was driving his daily driver and was turning off the interstate onto an offramp when the rag joint let go and he slowly coasted to a stop without using the brakes too hard in case they would pull it one way or another. Steering wheel would spin circles in his hands. This was a factory stock truck, not hotrodded or modified in any way. To tell you the truth, if it had been on one of his "hobby" trucks I think he would've noticed the rag joint failing way before it gave out. His daily driver doesn't get the maintainence or attention the old trucks do.
I wouldn't feel comfortable welding on a steering arm or pitman arm even if they are forged steel, but a steering column shaft or tie rod that has been properly shortened and reinforced by a competent welder wouldn't bother me. The steering and pitman arms receive too much leverage when the truck hits a bump or curb for my tastes.
If you hotrodders are worried about modified front end parts, you surely aren't using any of the aftermarket kits and parts out there, are you? Much of the FatMan's stuff scares me to death, especially the dropped spindles and steering arms for early Mopar cars. Most of the Mustang II crossmembers made(except Heidt's) give me the creeps too. Monoleafs make me wonder what happens when the 1 leaf breaks. Half the disc brakes and master cylinder mounting kits on the market look like they were trying to conserve on steel when they made them, the other half is pretty good. I guess you get what you pay for, if something seems cheap, there may be a reason.
If you don't feel comfortable with your welding abilities, you shouldn't tackle chassis work, or hire the welding part of the job out. And for sure don't use a 1956 welder like HRLincoln mentioned, there are much better welders made for these jobs nowdays.
