In order to install the motor mount we had to drill 5 3/8 inch holes. It was pretty difficult considering we were drilling through steel and the compartments were pretty tight. It took a lot longer than we though and in hindsight we would have designed the mount with 1/4 inch holes. We had to drill several holes and gradually increase the bit size to get our desired hole size. It was also helpful that we designed slot holes in the motor mount because the drill walked on us and our holes weren’t exact.