Mine is 74" without the OEM 3/4" plywood floor, vinyl flooring and ceiling sheet metal. --- must be shorter than 6' me thinks.My Bluebird must be a 74 inch one. With 1 inch polystyrene and 3/4 inch plywood on the floor I can walk through with an inch or two to spare. That's with my shoes on -- then I be 6 foot tall!