I have seen several discussions and more than a few 801 cowls that had issues with cracking at the fasteners.  I will share a solution that has worked well on 2 801s that is rugged, simple and cheap.

Use sections of piano hinge to join the upper and lower cowl halves and to connect the lower halves to the firewall, the  same way they attach cowls in the RV aircraft. I drill and with a few undersized screws, attach the hinge with the pins in to both sections. Once everything is aligned the way you want it cowl section to cowl section and bottom cowl to firewall, drill for the necessary number of flush rivets to attach the hinge to the fiberglass. Remove the pins, clean the contact surface of the hinge and fiberglass. Apply epoxy adhesive, insert and drive the flush rivets. Bend the  ends of the slightly over length hinge pins to 90 degrees. The vertical pins that hold the bottom cowl to the firewall will stay in themselves. The horizontal pins at the split line can be held in with one "tab" of the hinge material anchored with the screw that holds the front lips of the cowl together. It is very strong with no concentrated loads to start a crack. It is leak tight, the hinge is cheap, and you only have to uses screws or DeZuis on the top rear cowl to firewall connection. Cowl goes on and off fast and easy. Even in my crack up, the cowl connections did not fail or tear loose. The connection is stronger than the parent material.