from the 1970 car service specifications book...
10 different models of C4 for the 250, 302 engines
1. PEA-M2, PEA-N2, PEE-V2 for 302-2v w/12" converter
2. PEE-AD1, PEE-AE1, PEE-AF1 for 250 w/11 1/4" converter
3. PEE-M1, PEE-V1, PEE-AC1, PEE-AH1 for 302-2v w/11 1/4" converter
#'s 2 & 3 use...