On the bench for today will be mounting the cowl and the engine. I like to first mount the cowl and get it all centered on the fuselage. Then I stand the fuselage on its tail and place the engine on the firewall. Then I place the cowl over the engine and in place on the fuselage. I center the engine to the cowl opening and mark it.
This gives me a perfect centering with the cowl.
TB