Air Bleed Alternatives

So the 340 is running pretty good. But idle seems rich. Not going to try to drill and tap the 4150, so I decided to pop for a quickfuel SS vacuum secondary. Now I can tune easily with removable air bleeds.


So now the trial and error begins. And since it is a 4 corner idle circuit, I will need 4 air bleeds for each size I want to try. That is about $20 a set.

My question is. Why not use brass screws and drill. Or even nylon screws and drill? Or if threads are tapered at bottom the hole, brass set screws drilled? Or cap head screws that are stainless steel? Do air bleeds have to be brass?

Thoughts? Ideas?