Yeah I did it, can't find my original thread, but I used this stuff:
VHT
The finish has held up really well, no flaking or discolouration apart from the headers which are starting to rust (I had them shot blasted before I coated them which prolly didn't help). Remember this stuff isn't a 'paint' as such, it's a ceramic powder which 'melts' onto the metal giving you a tough and heatproof finish, but not necessarily a waterproof one like perhaps proper paint would - but then paint can't deal with the temperature!
This is it when I just did it.