Depending on if the TRE is tight in the steering arm hole or not woudl dictate if you can run it that way. I would think that if there was slop it would translate into poor handling and could eventually weaken the TRE.
Like I said, I had to get a pair of the alternator bushings for mine and...
When I did the swap, we just used the Ford alternator bushing and it worked fine. Had to put a washer between the castle nut and arm so that the cotter pin would be engaged with the castle nut.