The Krylon Wrinkle Paint is rated to 350F, more than enough for a valve cover.
I pulled the cover, sanded it with coarse sandpaper except the spark plug 'holes' and filler cap location. At those two spots I used my dremel and a wire wheel, along with the lettering to give them a polish.
I then masked off the 'holes' and the two middle bolt locations.
No primer is needed, you want where your painting to be sanded sort of rough (400-600 grit would be the highest)...this finish will hide most scratches anyway.
I wiped the whole cover down with lacquer thinner to remove oil and grease.
You put on 2-3 heavy coats and then wait....spraying about another coat every 5 mins (I did this about 3 times) then in about 15 mins (my temp/humidity) it starts to craze and wrinkle. (I put the valve cover on two crushed beer cans to keep it from sticking to anything and keep it stable).
Let it dry, but if after 2 hours the finish is not even (mine was), spray the other spots again.
I then around 2 hours took a razor scraper and took the paint off the lettering, then used slightly damp papertowels with lacquer thinner and my finger to clean off the rest of the paint.