During my build I had heard of issues with the upper cowl bowing up during flight due to the cowl pressure and the slack in the pins.
I also did not like the short pin on one side and a long one on the other with access through the oil door.
I copied a friend and added a small aluminum block to the top middle of the cowl. This screws to a bracket riveted to the firewall. Fiberglassing a lip for it to sit in this holds the cowl down and gives access to equal length pins.
Worked great for five years, holds the cowl from bowing up and make the pins easy.

Best picture I could find of the hole.