9 Since we are going to use the gray on the intake and black on the block, we had to decide which to spray first. After a trial run masking off the block and the intake we found it much easier to mask off the intake, so it will be painted first. Aluminum foil is going to be your best friend with a job like this as it can be used to quickly mask off all sorts of oddly shaped pieces. Lay it on the piece and squish it down around the part to be masked. It doesn’t get much easier than that.