Well I guess I am a bit confused between the parts book and the service manual
41 Shop manual
http://chevy.oldcarmanualproject.com/shop/1941/41csm279.htminstall the fiber shaft contact, spring and grease cup
42-47 Shop manual
http://chevy.oldcarmanualproject.com/shop/1942_47/4247csm1227.htm8. Install the bakelite shaft contact plug, spring and grease cup.
29-54 Parts book
http://chevy.oldcarmanualproject.com/1929_54chevyparts/02/153.HTM29-49 ALL
50-53 ALL w/216
50-52 ALL w/235
Specifies a felt wick, only the diameter changes (5/16 -> 21/64)
I thought the wick might be the one under the rotor at the top of the shaft, but the parts diagram on p. 154 clearly marks the plug, spring and cup as 2.364 PLUG, 2.364 SPRING 2.364 GREASE CUP
5/16's IS MUCH TO LARGE to fit in the grease cup.... so is there an error in the parts book?