I have replaced 4 or 5 tilt columns over the years. Tilt ones break more for me. The non tilt just last longer. I used to just go to the junkyard and grab a new tilt for $100 and swap it in. Decent junkyard tilt columns are difficult to find now. Your '75 is 43 years old now, finding good used parts is going to be tough. There are several different year breaks on columns which make finding a bolt in one that much more difficult. I have 1 truck left with a tilt and when it wears out it will probably get a straight one due to the economics of it. Its not worth the hassle to me to retain the tilt. Unless the bearings are totally shot leave your straight column alone while you are building the rest of your truck. Its one of the pieces that you don't really need, focus on the rest and splurge on a new column once your truck is sorted if you really want it. Good columns are expensive and rebuilding is difficult, its just the way it is.