Remember, this is a 340, not a big block.
What air cleaner assembly are you running? The base plate is smaller than mine. I have not tried to identify mine yet, here are some pics in case someone can tell easily what it is off, maybe it is an original AAR one as the 2nd owner did buy a real complete setup off a buddies Purple AAR in the late 70's.
Are you running the Vintage Air system? Did that compressor originally mount with the lines running straight up?
I assume based on what I can see of your belts you are not running power steering, what is the belt configuration on yours?