If the motor was hot tanked, go and get a base engine primer(gray) and then choose a engine paint that fits your needs. I have a B16A2 block sitting in my garage(for sale ) that was painted BMW M3 Blue(the Sky Blue) I did it myself and it looks Clean as hell, take your time and you will be happy, I dont care for the silver paint, but colors tend to look a bit better. BTW dont paint the bolts or any other parts on the block that are not part of the casting, if you mask them off it give a bit more look to the block and shows you didnt go crazy with the can of paint