Sure could use some help decipering the engine markings on what I beleive is a 65 300 cid. It appears the engine code is K P-665 (the 6's look like upside down "P's", or P-bb5. The Engine serial N0 is 4K4074677, again the "6" appears to be an upside down "P" or a small "b".
I am in the process of ordering major engine replacement parts, and would like to know exactly I'm replacing. Any help could be a life saver.

Here (http://www.buicks.net/shop/reference/engine_ident_63_75.html) are the engine codes for 64. Your KP is a high compression 300.

The serial # breaks down this way: 4 for Lesabre series, K for 1964, 4 for the Kansas City Assembly plat and the last 6 #s are the production # of the vehicle.