Has anyone installed removable seat backs for more room with a parachute? At 6'3 I 'fill up the cockpit' and could use the extra room when wearing a chute, likewise for the GIB.
If you haven't yet purchased your chute, consider a seat pack rather than a back pack.
Due to the seat inclination in the RV-8 the back pack will push you forward and up. This puts you closer to the panel and closer to the top of the canopy. Not a desireable configuation.
If you remove the seat bottom and use a seat pack you should be at the same seat position as when not wearing a chute. Or, if you decide to add a cushion to the top of your seat pack you will be pushed back and up, moving you away from the panel.