Re: the best under the hood paint in a spray bomb
I have had good results with the Satin Black Rustoleum under the hood. I took all the parts to bare metal, cleaned with acetone, used Rustoleum primer, then Rustoleum Satin Black. I think it looks great and after 3 years there is not 1 spot where it has peeled, bubbled or rust broke thru. You can achieve professional results with spray can paint if you do your prep work and it cost half as much if you will buy it at Walmart or one of the big box discount stores.
As far as the engine I used the VHT and it has held up great.
If you have rust issues, treat the area with POR15, One Step or any of the rust converter products. I have even had good results with Rustoleum Rust something in the spray can.
1967 Galaxie 2DHT w/460
Chopped to make a rag top
2013 F150 Platinum
2007 Jeep Commander (wife)