1965 Dodge Dart Charger

NOS master cylinder for 1965 Dodge Coronet w/power brakes.

That's correct for your '65 Dart with power brakes, too:



As for the piston seal: I suggest you grab a NOS booster rebuild kit p/n 2075 001 from Valley Vintage Auto Parts, then duplicate as many of the O-rings and seals as you can with nice new ones from www.smallparts.com .