Consensus confirmed, moving right along... That air box does not have "built in velocity stacks". Those are two plastic dodads that reduce intake noise and further restrict air flow, pull those out, drill a few more holes, remove a coupla screens on the metal mesh filter, drill a tiny hole to let gas drain out on the bottom of the box and turn the damn box away from your sidecover. Now save those plastic spacer things to use later, good for sidecovers, spacing stuff out,like mounting license plate without scratching, etc.
Read up on porting cylinder to go faster. Read up on how to dress you cylinder and stock head for a good seal.