You need high temp paint. I remember seeing on the show "Trucks" Stacey using PPG paint to paint the engine but it wasn't regular paint, it had the same paint code but if I remember correctly it was for high temp. If not then it will bubble and flake off. We just got a Vette back in the shop where the hood bubbled because the guy is trying to run a 11.5:1 comp ratio engine on the street as a daily driver and it's overheating so in turn is getting that fiberglass hood scortching hot. So if the hood is doing this then so will the block of course. PPG should be able to color match it for you and get high temp. I like a car where the engine compartment and engine are painted the same as the car. Should look very good when your done!