Hi, and Thanks for the help. The engine is in a 1974 F-100 truck. I believe it is original to the truck. The title and door vins match, but on the tag found behind the engine the 5th letter changes from an R to a P. Other numbers on the tag are as follows :

F10YPTO4658 26-116
YX 133 BDY 4 WDE
MN DLX RPO CUS
C X E ? J MID AFT

( between the E and the J ( where the ? is ) in the last line there is a cutout that resembles a 6 )
It is also a side oiler.
Do you have any idea what D2TE-AA stand for ? From what I've read the AA stands for PI side oiler. Does that sound right ? Thanks for your help.