Several steps involved Joe, first off soak it all in Gunk Carburetor Cleaner over night, (at least 24 hours). Then attack them with the scrubbing bubbles, that be New Blue Cheer in some hot water and a SS wire toothbrush and stiff parts brush. After a good rinse that does it for the Zinc castings or any thing that isn't rusty.
For the parts that are rusted, like the throttle body and linkage it goes into the D-Rust-It tank. A couple of hours are usually good if it's not to terribly corroded then back to the scrubbing bubbles.
At this stage you will have a throttle body that looks like a new casting with a rather flat cast gray finish. You can paint it or the other steel parts if you choose with cast blast, or an black Rustolium, or a clear, or plate them or just leave them bare to rust like most of the new ones were.
I some times follow up with a fine wire wheel on the pedestal grinder as I did on this one. Although the original cast iron parts were left bare I feel it helps to keep it looking nice if you do paint the throttle body.
As far as coloring the Zinc castings, I haven’t used any of the Eastwood products that simulate the yellow or yellow green chromate finish. A lot of the new Zinc casting are treated with a chromate or conversion or anodic dye I haven’t found any sources for these chemicals. Perhaps Jon, the “carbking” can give us some advice on how to treat the Zinc castings to make them look new again. That certainly would be the finishing touch to a well-done rebuild.
Denny Graham
Sandwich, IL

Denny G
Sandwich, IL