I am in processing of getting 1965 cuda to restore seller states it has a 318eng. all information I find states 65 came with 273eng.  This is my first mopar so I do not know. Please help.  

I really doubt it had a 318 poly in it. 318 LA's did'nt come out till 67 which replace the 273. If it is a 318LA motor, someone put it in.

In 1965, the only V8 engine offered on the A bodies was the 273.  Poly 318s were only used in the B & C bodies.  Like the previous poster stated, if its a 318, it was transplanted in.  

Doubtless, it was a 318 Poly!

You may find these links helpful...

The Polyspherical Engine association (there's a list of places to find parts & info):
http://www.geocities.com/polyman64/

At the top of that page you'll find the following links.

The 318 Poly Yahoo Group (which is where we all are (ask us ANYTHING):
http://autos.groups.yahoo.com/group/318poly/

And the Poly Forum, where we'll all lurkers, and casual posters:
http://www.diamondbackengines.com/forums/index.php/board,6.0.html

More info at the sites above...

~Jason