Aircooled vanagon engine


New member
I recently got a 83 vanagon that has had an aircooled swap. The engine has a really bad ticking/knocking noise so I have pulled it out. I have been trying to look up as much info as I can but i still have some questions.
-any ideas on what the noise could be?
-is there any difference between and aircooled vanagon engine and a late type 2? (Serial starts with GE)
-what are the fins on the exhaust for?
-what are some good things I can do to the engine while it is out?
-anything else you can tell me about the engine by looking at it