My Crow seatbelts have 1/4 inch holes to mount to the plane. The holes in the mounting tabs on the plane are also a quarter inch. The plans however show using a 5/16" bushing in the seat belt bracket. I would have to drill out the hole to 5/16 to fit in the bushing. Is there a reason why I can't leave the bushing out and just put it all together with the AN 4 bolt. It seems to go together just fine with no bushing. Trying to figure out the purpose of the bushing. Does it protect the bolt from wear from the seat belt bracket? The crotch strap bracket doesn't use a bushing.