The block, heads, intake manifold, carbs, water pump, etc. are sprayed with a flat clear (I like Citadel's, expensive but good stuff). Everything but the carbs gets thin washes of black until it looks right. The carbs get a wash of brown. The intake was then drybrushed with rather bright metallics (Citadel again). Spray again with the flat clear. The valve covers and air cleaner (anything chromed) were sprayed lightly with flat clear so they still have some shine, like dirty chrome, and then a thin black wash. Thicker washes of black were used around gaskets.
I filled the back of the exhaust manifolds with sheet styrene and then drilled out where the hole should be, where the exhaust pipes bolt on. Paint them flat black, dry brush with dark and light brown so they look rusted, and finish with some light brown or tan pastel chalk so they look dirty.
The antifreeze spills were done with a wash of one of Citadel's greens, I don't recall the color name, but it looks just like antifreeze.
The flywheel was painted with Metallizer Steel, given a black wash and dry brushed a light metallic on the teeth and surface.
The bolt heads on everything but the exhaust were painted steel.
I did paint the water pump aluminum, I thought that looked beter than the orange it comes in.
I think that's everything, its a lot easier to do than describe. Give it a try, they're good kits and east to build. I built this one completely out of the box except for one of the fuel lines on the fuel pump: It was missing, so I replaced it with a piece of wire and a short lenght of shrink tubing for hose.
Hope this helps.
Vern