Hi Mark It was nice meeting you and others at Oshkosh!
I flew a C150 once that did not have an EGT meter. every 1000vt I pulled the mixture back slowly until the engine started running rough, then pushed the throttle back just 6mm. On my Cessna 182 I find it difficult to see where the EGT peek. The AMO told me I ran the engine too lean and burned an exhaust valve that cost me R34000.00 to repair (That is $4250)