This is a quote from my post above. "I remember your early discussion on the plug gaps and didn't realize at that time the gap depends on which plug is installed."
I have done some additional research in both volumes of my 2004 Tacoma shop manual. The gaps do not appear to be plug specific as I mentioned. In volume I page SS-30 the information is as Mike posted above. DENSO K16R-U11 or NGK BKR5EYA-U. The recommended plug gap is .043" for both plugs. In volume II in the ignition section for 2RZ-FE and 3RZ-FE engines on page IG-2 the same plugs are specified but the correct gap for both plugs is .031". Obviously one of these recommended gap settings is wrong. For the 5VZ-FE engine volume I on page SS-32 the recommended Plugs are DENSO K16TR11 or NGK BKR5EKB-11. In volume II page IG-3 the same plugs are recommended with gaps set at .043". I think the .031" gap is an error. Most vehicles have used plug gaps of around .043" for several years.
I have a 2002 Mazda Protege 5, recommended plugs are NGK BKR5E-11, DENSO K16PR-U11 or Champion RC10YC4. The gap for all plugs is .043".
FWIW, I made some ohm-meter measurements of a NGK, DENSO and Bosch resistor type plugs from the top lead connector to the center electrode, all showed infinity resistance.
Clifton