I am having my intake - cast iron 9794234 shot peened.

What is the best way to suspend it to spray paint it?

And what is the best way to wash out the shot peen residue?

If it was aluminium, I could just wash it out with water or vinegar. But it is cast iron and will flash rust

shouldn't have to hang it. just tape off the intake ports and carb flange, do one side, let it dry and flip it over. use compressed air and then some brake clean to get it cleaned out.

1. Ditto on the spray brake cleaner. Those cans put out a lot of volume that washes down media-blasted parts in a hurry and then guess what...

it all evaporates. No water so no flash rusting. I have been using this method forever. The cans are cheap, too.

2. I have thick wires hanging from stratigic points in my garage specifically for hanging and painting parts. Being an engineer - I always overbuild the "erector sets" that secure my garage door opener motors - so those structures make good hanging points. Others are open garage doors and "A" frame ladders.

When I do mine, I bake them first at 550 for 20 minutes, then cool for half hour, then into the shot blaster. After that, we have a tilt/roller than gets out all the excess shot.

Compressed air in all threads. Chase out threads then brake kleen in thread holes first, then remainder of intake.

I tape off the carb base and intake runners and use a set of spare bolts and insert in all threads. Use an exacto knife or razor blade to trim excess tape.

I usually do one side at a time. If you spray the top first and have a set of 4 bolts installed at carb mount, flip over and let the intake rest on that, then shoot the bottom.