I agree, but will note that in addition to vintage OHV Chevy stuff, Langdon's Stovebolt sells dual carb kits, HEI electronic ignition kits and reproduction Fenton cast iron headers for Mopar flathead sixes.
And Mopar Montana sells other Mopar flathead speed equipment, including performance reground cams and new Edgy finned aluminum heads.
In case you want to mess around with the old flathead six instead of swapping in a more modern motor.
