I'm doing that A/F Ratio mod today! I'm getting an "Anti-Fouling Plug Adapter" from Kragens for $4, and having it welded in JUST after the header collector. Although I'm not hooking up an A/F Ratio Meter, I am having my friend who has a WideBand OČ Sensor, hook it up and we're going to tune the carb to be Stoich @ idle/cruise/WOT.
It's nice to have friends with such expensive toys

BTW: On that Tranny temp sender, I personally would put it in the pan.