1987 throttle body bushings
 

I'm sure this has been discussed 2.7 million times, but I can't seem to find good answers anywhere. Is there a bushing kit for the throttle shaft on the throttle bodies? Mine is pretty sloppy, and I'm about to rebuild it so I want to fix that while I have the whole thing torn apart. If you have part numbers or links for bushing kits that are guaranteed to fit, that would be great.

I've also heard that 1991 and up throttle bodies are a little bit of an improvement over the 1987-1990 bodies. Can anyone confirm this, and are they a direct swap? I don't want to run into any mechanical/tuning issues with it.