In a pinch use the phenolic motor shim that comes in stock motors. Ream it so it doesnt rub the K-pin 1/8th is just right. Covers the whole ball/pivot and keeps all the crap out and a nice flat surface, works great. On the botton ant thin shim will do depending on the Amt of pre-load you need.
I personnaly put a retainer between the spring and the bottom a-arm so the force is applied directly on the bottom a-arm and not thru the pivot ball. First thing you'll notice by using a retainer is that the pivot ball is a lot less stressed under load and that it is likely to last longer.