[Roger V]

Some have had a "custom" two inch thinner seat back cushion made to help with this but mainly to help with leg room and steering wheel clearance. Since the stock cushion is made with springs, Snyder's Antique Auto Parts may make this for you (they were the only or major manufacturer of seat springs). It would be less expensive to have your local upholstery shop make one out of foam and cover it with material similar to the bottom cushion (if original type, you can buy bolt material from LeBaron-Bonney).