I'm in the same boat with my '65 cuda... I think the original mopar 4bbl part is #2465726Summit carries the offenhauser's that fit the
'64-'65 273 motors. I found three on their site:
http://www.summitracing.com/
#5697
#6023-dp
#5488
Best of luck finding one used for a 64-65! If you find two cheap, I'll take one...
