Also if you do some google searches you might find out. If I remember correctly the last three digits on the booster was 268 and painted flat blackI’m not 100% sure but you might find out here
International Chrysler Collector Authority ICCA ©
MMC Detroit
Unfortunately no photos of a 71 440+6 E body.I’m not 100% sure but you might find out here
https://mmcdetroit.com/ICCA/References/Engine_Compartment/#pop01
MMC Detroit
Unless the original owner changed mine, it is cadmium plated on my August 10th of 1970 built 1971 340 convertible. No numbers on it that I can find either. Mine also has the 1970 style console with seat belt cutouts.I think it's generally accepted that early cars got the Bendix booster and it was painted black, while later cars got the Midland Ross booster and it was plated / unpainted - some have said January was when the changeover happened.