Cabin top thickness on my boat.
Tim, Call me crazy but I save all the plugs from holes that I've drilled in my boat and I the one from the starboard, aft of the cabin top right here in my hand is 7/8" thick. So I'd say that 1" would be a safe thickness to work from for your clutch installation. Bon chance, Glyn Judson, E31 hull #55, Marina del Rey, CA