I have heard that the transmission oil in the right side can help keep that side cooler. If you have verified there are no air leaks, compression, squish, etc is the same, just run it.
Your information is off. You say that right cylinder is lean but you have to close the PJ completely, while the left is open.
Can you clarify this? Sounds like the left is lean and the right is not.
Just stick with the stock cylinder. If you already have a 421 Serval, there's no reason to bother with the 392 Athena.
I just don't understand why you'd want less power than the Serval.
Right now, Carmack is the only one making Snipers. He's a young kid buying stamps directly from Gary but he's not in a position to pay for everything up front.
Right now, there's about an 18 month wait on them. Carmack Customs here on BansheeHQ is who is building them. Gary actually called me today about some other stuff but he's hoping someone would step up and do 100 sets. He just can't physically build them that fast anymore.
Some things to factor in when going bigger.. The chances of breaking shit goes way up. Cranks, transmissions, chains, etc.. Literally everything can and will break easier.
No sense in doing the 7mm. Just do the 10mm since the cases need trenched.
Smart Carbs are junk. Stick with what's proven, Keihin PWK.
You'll need CPI, Snipers or Shearers.