isn't the "4P" an SS with a 350? or am i mistaken??
...one of the reasons for my post. "4P" does not always mean SS.
In the case of the L30/M20's, they were not SS's (no SS 327), ...but they did receive the 12bolt with traction bar, ..therefore the later (I believe meaning after January) built cars did get the "4P" cowl tag code.