It was my belief that 1953-54 Vettes did not have manual transmissions, only powerglide automatics. Am I wrong?
No, I think you're right about that but I always figured this car had been altered (as some of them certainly were). If so it would be the 2nd 54 Vette I knew about with a 3 speed. The other one (which I rode in a few times) belonged to a fellow who bought it new and ran the Sears auto center when I was with Sears in the 60s. As I recall, he bought it for his wife (who preferred the automatic) and then paid to have it converted after they had a kid and she needed something more practical.
I've seen mention of cam timing somewhere before, but I can't find any data in what I have. I even dug up an old Chilton's I've been threatening to discard since the 70s and there's nothing there either. Thanks for the help, though.