Did you soak the tappets in new oil. Not 100% sure but think your supposed to compress them and try and get all the air out and some oil in new tappets. That way when you try to start the engine the tappets open and close the valves properly until the engine starts and gets proper oil pressure up to the head.

Also have you managed to get the engine to start? and if so did you run the engine @ 2000 rpm for 20 mins as per cam run in instructions ?