65 nova engine codes

i am looking at a clean 27000 miles 65 nova 4 door to buyfor a daily driver. It has a straight 6 in it, the owner claims it has 27000 original miles, the body is super straight and clean, but the pictures show the motor to be rusty, and unkept looking, when i pick up the car, i want to check the engine codes, and compare the block code to the vin tag to make sure its the motor the car was born with. Where are is the block codes on a straight six?, and will the vin # and block codes coincide? thanks for any info, Dick