Hey all hoping someone has seen this issue. Here is my series of events. 

• 3300 engine runs perfectly smoothly 
• upon annual inspection I find the scat tube going from air filter to carburetor has failed at the very spot the carb and scat tube meet, meaning I had been drawing raw air into the carb.
• I replace the scat tube and I get a very rough running engine at high rpm, a known problem published by Jabiru where the scat tube creates disturbed air just before entering the carb. 
• I replace the scat tube with the crosshairs air intake tube sold by Arion Aircraft which smooths out the airflow just before entering the carb.
• now I have engine max rpm issues where i have these issues,
  • I can’t reach max RPM, even when I push throttle to the wall, I hit about 2800. 
  • even at 2800 I have engine roughness and not the smooth high rpm the Jabiru is capable of, though it smooths out at lesser RPM around 2300-2500. 
  • i am missing some power, I can’t cruise at my normal speed, it’s not climbing or cruising like it did.
• In other news, my EGT has taken a nosedive, down to 300-400. Yes this could be related. It could be a bad gauge which do go bad often. Any correlation?

Questions

• Is my air filter dirty? I’ll check soon but the massive drop in performance makes this seem odd given the FWF kit was done about 30 hours ago.
• Do I need different carb jets/needles now that I have a different air intake journey? 
• is there another issue like jammed spark plugs (which were fine at annual) or some other issue that I’m not thinking of?

any thoughts are appreciated, it’s driving me crazy.