1) Quit running water! Your truck needs either antifreeze or something like "water wetter" (
http://www.redlineoil.com/Products.aspx?pcid=10) if you want to keep using water.
2) You only have a 4 blade FIXED fan on the truck which may not be enough cooling now for the truck.
3) You are running a aftermarket performance cam so you could probably run 16* to 18* base timing and be ok.
Don't forget that you did a lot of stuff to this truck that can affect other things in a negative way; For every action there is a reaction.