327 Decoding

I have done some research as to how I can figure out exactly what 327 engine I have but I am not sure if I understand it correctly. I think I have a 1968 327 (3914660 casting number). 18T247922 partial VIN. T0509HA engine code. If I am correct this information tells me I have a Tonawanda made 275hp 327 made on May 09, 1968 for a full size/Camaro. Can anyone confirm this for me or steer me in the right direction?

Thanks
Jay