I saw the question asked many years ago but don't recall the answer - "What did the different letters mean and were they casting # specific?" I don't normally use the letters as a reference, just the casting #'s because it gets confusing. Anybody have any additional info?
'68-'70 340 = 894
'70-'71 (-
'72) 360 = 915
'70 T/A = 915
(
'71-) '72 340 = 915
'73-'74 340 & 360 = 587
As far as I know, only the 894 X head had "340" cast into it while the rest had "360".
I borrowed these pics from another members post a long time ago. I believe the story was that these original bare X 894 castings were machined with T/A intake pushrod locations by Mopar during development before 915's were available. Only 915's were eventually used on T/A & AAR production cars.
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