Ok so we used the 1965 Rule book basically because it keeps guys from putting 400 lbs of batteries in the trunk. Also if you were building a car in 1964 you would be building it for 1965. Agree on the later 327 block, the 350 block may be the same but makes the tech job harder. We are not tearing down motors, that is crazy for a trophy class. I love your "Spirit of the Rules" idea and it really is covered in the rules allowing re production parts that are identical to the original 1964 stuff, so your Top Loader is an fine example. For the 9 inch ford Rear end, you are correct in that one can take a same size 9 inch and have it made to the width of say a 1959 Ford. We just don't want the pro street look. Thank you sir!