The bushings may be available but you might also need to hit a junkyard if there are any in your area. I just put in my 96 brake/clutch and found that it was sloppy so I need to find the same part...I know I had the bushings (there are two or three in there) when I started but...well, there's a mystery in this one...
Check LMC or Rock Auto...if anyone has them it will be them...but I'd imagine any plastic sleeve that fits snug and doesn't bind will do...the ones from my 88 fit the shaft but they were so brittle they broke.
Have you got the part out of the truck or is this a planned replacement for some time in the near future?