1964 chevy impala ss engine casting/ manufacture number?

[Michael]

I have a what I believe a matching number 1964 impala to the 936 paint code which is white the 14 for hard top ss etc. The int is orig. The transmission I went under and seen it said power glide on the passenger side. I want to know if this is the stock motor it came out the plant with. I check both sides of the motor it's orange in color looks stock but no stamp ya know. I'm pretty sure it's a 327 chevy motor from that era. However I'm starting out and need help on a website I seen the manufacture date on the motor to the cowl tag date would tell you if it was stock. The car had the orig shocks and what I belive to be the stock power glide. I want to make this car a true matching history car so many have been changed that's ok but stock numbers is history. Anybody tell me in the best description possible where the numbers would be and what they might look like. It does have a aftermarket intake and carb. The exhaust off the motor makes it hard to see anything on the side stamped. Thank you