[60 Biscayne]

A wise man once said "Become master of the obvious & you will be one of the smartest".
Your seat can go back as far it has no obstructions!
If there is a ledge it will bang into thats as far as it can go w/o raising it up which you at 6'7" don't want to do!
If you slide your seat all the way to the rear and it could go another little bit (ie:4") before it will hit (the ledge etc.) - this can be accomplished by mounting the seat to a flat plate (ie: 1/8" steel or 3/16" alum) and than drill the holes for the track to mount in the plate positioned so that the seat now goes back further and all you've added id the thickness of the plate.