Don't know that I've ever seen Delrin bushings on the shelf. Most people make them. The stuff machines incredibly easily. Delrin is a trade name, the polymer is called Acetal. Should be able to buy small sections from McMaster if you can't find it locally.
We have some assemblies at Baja Concepts. They run about $38 or so. They have 1 3/4 4130 with delron bushings and sleeves we have some for a 3/4 bolt right now. But can get for 1/2" bolt also. Call me if you have questions: (760) 723-2117
does delrin need grease like a regular urathane bushing does? i was told that it didnt but am still not totally coinfident it doesnt. i had a machinist friend make me some bushings and he just copied regular urathane bushings, he put the grease slots/holes in the bushings. this was before i was told they didnt need grease.