At 6/3 and 250 and 65yoa, my 3rd gen with moonroof/sunroof has plenty of headroom to make travel comfortable, but understand opinions may differ gen to gen. So, pull the seat, pull the carpet, draw straight lines to set up a square defined by the bolt holes, draw a second square fore-and-aft on left and right and left-to-right on front and rear, one-half to one inch beyond the edges of the seat frame's maximum travel (or be prepared to accept limits on the travel). Check clearances underneath, pull out the trusty plasma cutter with asbestos shield and remove the floor along the outside lines laid out. weld the bottom of a one to two inch spacer around the lip of the rim of the cut out floor section, then weld top of spacer back to floor, creating a cup for the seat frame to sit in, bolt the seat back in and see what you have wrought, lol. Measure twice and cut once. It would seem to be easier done when a lift is in place. Please understand, this is an off-the-top-of-my-head intellectual exercise to generate a discussion and development of options, the clearances underneath will dictate the drop allowed, each gen and model will be different. Not sure its possible or plausible, but regardless would be a whole lot of work for an inch or so. And may seriously weaken crash worthiness, so do at your own risk.
