Answers

So that I can better answer your question, can you further explain what you mean when you say "cap over". I am thinking that perhaps you are referring to the horizontal trim piece between your siding & the top of your foundation, but am not sure. 

I would suggest construction adhesive which will attach the trim boards while also providing a capillary break between the block and the trim board so that moisture does not wick into the trim boards.  I would also suggest installing the trim boards at an angle to shed water away from the house.

You can also use Tapcon masonry screws.  Pre drill. Countersink if you want to hide screw heads with wood filler or Bondo.