The seat is as low in the bracket as it can be. I'm 5'8" and with full tilt back in the bracket I have an inch from the roof with helmet on.Hey Steven
On the seat - are yor brackets on the right side of the seats and a higher bracket could be to the rear.
Then locate the hole bracket an inch higher and you will manage to fit seat runners (possibly not motorised but manual should work. (needs 1 inch clearance)