[Flatheadsix1949]

I have two old flathead six engines that I know are plymouth but I can't figure out what kind of car they go to. The number on the driver side top corner of the 55 engine is P26-84......
and the numbers on the 54 is p25*16...... I'm not sure what all these numbers mean and if anyone can help me identify what model they went to, it would be a big help.

 

[ImperialCrown]

I haven't put my hands on the service information that I'm looking for, but the P25 is a 1954. There was an early and late 1954 with a change in displacement.
P26 is 1955 and was the larger displacement.

 

[Flatheadsix1949]

I read something about a diamond being before the p25 if it's a 230 and mine doesn't have that then can I assume it's a 218? still has a 23" head