Ask to speak to Tom Hannaford when you call. He had some made for or Plymouth's a while back. Be sure they have been modified to ensure the gear will not spin on the heb.
Vintage Auto Parts also lists them for 28-32 Plymouths for $198.75
http://www.vapinc.com/
The only way I know to change it is to pull the engine, remove the valves and oil pump and pull the camshaft out, then take it to a machine shop to carefully have it pulled off. Stay with it, as it is hard to get behind the gear to remove it and the shop broke the bearing flange removing mine a few years back.
Vintage Auto Parts also lists them for 28-32 Plymouths for $198.75
http://www.vapinc.com/
The only way I know to change it is to pull the engine, remove the valves and oil pump and pull the camshaft out, then take it to a machine shop to carefully have it pulled off. Stay with it, as it is hard to get behind the gear to remove it and the shop broke the bearing flange removing mine a few years back.