Glyptal & best way to apply it?
Read the instructions from the paint manufacturer. A lot of paints require curing processes. Example: header paints get a bad wrap for not lasting long, but if you read the application requirements and curing requiments, you have bake the paint which most people don't bother to do.
Also Red Glyptal is not a block paint, its for electrical motor armatures- it's just something that old hot rodders did back in the day with the junk the had laying around that was better than anything else available. Go to the actual glyptal sight and look for the coaching that matches your needs, or better yet call them and talk to a sales rep about what you need.
As with any paint, surface prep is paramount too. Also chemistry. Some paints are happy to be around oil but the second they come in contact with coolant they start unbonding so you have to be careful with your choice if you do rebuilds.
As PBR said, painting is not gaining you much. Oilophobic coatings are hard to come by and most OEMs don't bother. A good polish of the surface will get you what you are after with oil return and no worries about paint flaking off and getting caught in the screen.