Tell tale signs

[driver007]

How or what is the best way to id a AMC 232 i6 verses a AMC 258 i6 / 4.2l . I am buying a 77 CJ5 and am not sure witch motor it has

 

[Saddle Tramp]

On the right side of the block between #2 & #3 near the head there is a machined flat surface with the engine build date code. The size of the engine can be identified by the 4 character. 258 = "A", "B", "C" or "M". 232 = "E", "F", "K" and "L"

 

[driver007]

Thanks I did not realize they were one in the same. I was hoping for a clue. I just can't get at it for awhile thanks.

 

[Saddle Tramp]

The 258 is really just a stroked 232 so it is impossible to tell the difference from just a casual glance.