[vettestr]

Reading plugs is an art but only possible under fixed conditions and of small value with electronic injection. I see you are running a carb so suggest purchase of a stand alone 02 monitor for about 100 bucks. Then pay close attention to placement of sensor as too cold exhaust gases are very misleading.. You can just intall sensor and then use a digital VOM to read output. A 2 wire or non heated sensor is only about 30 bucks and can use your high impedance volt meter for test readings. A buddy can jot down readings under different drive conditions but then you have a hole to plug in exhaust when senor removed. They are the same thread as a spark plug 14mm if this helps. In the long run take it to a trained ear or pay for a chassis dyno