i am thinking of going with sag steering in my 40 can I use a steering column from a 72' 55 that has a u joint on all ready or is it easier to just cut mine or is there an easy way to do sag like a custom column ???
you need a 9/72 or later FJ55 donor for the column. The earlier will not work well and don't accept the steering wheel etc from the '75 FJ40.
also, a number of mini truck intermediate shafts will work.  rill the safety spot welds out, slide (or cut and slide) to right length and re "plug weld". I would not use the stock FJ55 U joint bolt on deal.
...for FJ60 type conversions, the sweet intermediate is the 1985-1990 J60/2 shaft...