When switching the hubs from manual Warn hub back to 3 screw auto hubs can I use the 3 piece spindle lock nut or do I need the single style lock nut?

 

You need the correct auto hub wheel bearing nuts
Most people swap the other way and in fact I have a set of good auto hubs and all the small parts you need (I think) in my storage totes
Yours will be the style with one big nut that has the grooves to accept the locking half moon cog
Do not forget to lube those auto hubs with the special auto hub grease when going back together

 

This is from a thread back in 09 on this site
Found it on google looking at images of 1996 Ford F150 auto hub wheel bearing nuts