Prep and paint of '73 Harley engine

Hi and thanks for taking a look at this. I'm rebuilding a '73 Harley Davidson and I've stripped it down completely. The engine paint was badly chipped, so I had the parts sand blasted to bare aluminum (the cylinders are steel though). I like the look of them now (light grey) and I'm wondering what I should do next - Paint, Powder Coat, Clear Coat? Also, are there any drawbacks? What about overheating of the engine? The case is not smooth by any means. Do I have to make it smooth before finishing?

I'm brand new at all this, and the bike belonged to my brother who has passed and I want to do this right! Thank you for sharing your knowledge and experiences!

Steven, Sorry to hear about your brother. I can't tell you what to do, but I can tell you of a web site that can probably help you out. J-P Cycles has a forum on their site for restoring old bikes. Good luck with your project.