I just saw a new in package mc28 jet kit on an auction site in Japan for $1000 usd. And if you scroll down a bit another seller is putting up a two sets on mc28 carbs one with jet kit the other without, all for $800usd. Seems like a no brainer if i was in the market.

I have the dimensions for the hrc airjets....we should make some. Im working on mc28 needle holders. Might be few months cause i have a day job. I dont plan to get rich selling them so they will pretty much be priced cheap..

Air jets could made even easier.