It's a 2bbl, the only option in 64. Probably not much more power than the /6 for that year.
I did a little more inspection underneath and might be a little too rusty for me. It's all there though. I did a little google search and found out that a place in Michigan makes a lot of replacement panels (floors, quarters,...) for the early A's. There name is Classic 2 Current.
Here's a picture of just behind the rear leaf spring.