Hey Ben,
Welcome to the troublesome world of suspension bushings
These have been discussed over and over and over, and yes, they are known to bind
There is no easy way out... you'll have to make them fit as good as you can.
Basically what happens, when you press the bushings into the arm, the inner diameter of the bushings change.
So you'll have to sand, file or machine the inner surface so it matches the outer diameter of the shaft.
If the bushings bind, the suspension will squeek, and does not function optimally
Make sure you have the bushing grease/lubricant, and make some grooves on the inner surface of the bushing (use a dremel tool), so there is a little 'gutter' to keep the grease.
Some people even install zerk-fittings so they can add grease without needing to take the suspension apart.
Check this thread, I think you'll find some usefull info there. Also mention what's said about trimming the outer surface of the bushing where it meets the inner suspension 'ear' to avoid the ovaling...
http://www.914world.com/bbs2/index.php?act=ST&f=2&t=292Browse back some, or do a search on "bushings" or "suspension" and you'll find more info
(info on the front suspension bushings is just as usefull, so keep reading!)
I'm sure others will jump on this thread as well...
And when in doubt, don't be shy to ask
cheers,
Jeroen