273 exhaust flange gasket

I have a '64 Dart with 273 2v engine. I'm having difficult time finding exhaust flange gasket for my 273. Parts houses have exhaust flange gaskets for slant 6 and for the HIPO 273, but no listing for the base 273. Think mine is the 2.25 diameter exhaust. The gasket goes between the Y pipe and exhaust manifolds. I'd appreciate any information such as mfg and part number.