The UKC lo206 drivers mostly run Tony Kart/FA/Kosmic and CRG. Those are also the chassis the local shops run. Go with a chassis that has the local support.
A too rich condition can limit the pull to where it won’t get into the second ignition timing. To test, use enough rear teeth so it can easily rev all the way up on the straight (like 2 or 3 teeth more) and go 2 jet sizes leaner.