I used the large camloks (Phillips head) which come with conical washers for
the top and  bottom of the cowling , hinges and pins for the sides, and four
10-32 screws at the spinner end  to attach my cowling. It has been
absolutely and totally perfect. Don't know why you would use any other
unless you want to make it all invisible. My cowling always goes back on
perfectly with the camloks dropping right into place.

Fred Egli LIV N1228E ~500 hours, 6 years and minimal maintenance required.