Swapped from a b16a2 to a b16 sir ii head, need to redo my valves I think... at 3k rpm it starts to make a weird rattle/humming sound (i honestly don't know how to describe it) but you can hear it.

Also whats a good body filler to use.. I'm going to try my hand at fixing these dents next!

 

Check your valve lash and lmas