After market seats not sliding back far enough

[Cableguy114]

My 1975 EB had he TBP custom deluxe seats in it when I got it and they look great. The drivers side seat just doesn't slide back far enough. I have taken the seat out to verify that the sliders are pushed back as far as they can be and they are. I am only 5'8 and I need more leg room, I can't imagine what it would be like for a tall guy. Surely someone else has had this problem and has some ideas.

 

[ScanmanSteven]

What I did was weld extensions on to the base to allow new holes to be drilled so the seat physically sits back further. Just butt some 3/16 plate up to the seat base and weld it on. I unbolted the seat and slid it back until it was comfortable, marked it so i
when it moved when I got out I knew where it went and added the extensions.