Mask the intake and harmonic balancer and paint the rest. Spray some brake cleaner on an old T-shirt and wipe off anything you don't want paint on after painting.

I use a belt sander on the valve cover fins, spray them and wipe off the sanded part of the fins. Nothing looks worse than big old ugly aluminum heads, water pumps and valve covers on a nice Mopar, except aluminum radiators.

1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)