Upper Arm Shaft and polyurethane bushings

Question:

For replacement of the upper arm bushings on the shaft, you of course just burn them out and put in the new bushing cores which are polyurethane.

Should the shaft be replaced at that time?

I ask because I had my Torino aligned many years ago after a front end rebuild I did myself. I had clamped that shaft to work on the arm, and after all was said and done I had it aligned at a shop. It was a good shop, older guys working there, grandfather had been doing business there for 20 years or something.

A week later the car is leading to the left or something like that. I take it back in, and the 60 yr old guy doing alignments tells me it shifted because the serrations on the bottom of the shaft where it sits on the frame were worn off and would not bite. He realigned, tightened the two bolts very tight and it was fine. Later alignments before getting rid of the car I always requested those bolts be very tight.

So, not that I have clamped the arm shafts on the current project, but should I replace the shafts to get new serrated shafts to ensure "bite"?

I am getting ready to order parts, which is why I ask. At 60-90 bucks a shaft kit (only way to get the shaft), I could save an easy 150 by not replacing, but I am going for 100% replacement as necessary for zero rework 5 years from now. Cost is not the top option - quality is.

Thoughts?

I will keep updating on this matter, however, the current status of the arms is as follows:

The folks at Suspension Restoration told me to burn out the old bushings to keep the outer sleeves in (for the new polyurethane cores to go into). He insisted it was the easiest way to do it. So I did:

I burned the heck out of one upper arm's worth. I fried the bushings to a crisp, but they never popped out like advertised. In fact, they turned to carbon still in the original configuration. I will try and get the material out to see if it worked, but either way, I will be replacing the upper arm shafts because after the torching they took, I know I heat treated that steel - not good. I think the arm was OK, but those shaft ends took a heat beating for sure. I let them, burn, started them again, let them, burn, etc. Anyway, I will post status reports as I proceed (and perhaps some pics as well). So far, not living up to the expectations. Those bushings will get out, but not as easy as I thought.

I usually use oxy/acetylene for a few seconds... the bushing ignites nicely, then launches a foot or two.

OR... a metal bucket with 1/2" full of gas.. dunk the control arm end, submerge the bushing, then ignite.