motor: 383 with 10.5:1 comp, afr/tpis heads, ran with 91 octane
has msd 6a box, with blaster coil.

I was originally running tr55's with a .45 gap
Then i was told to change to tr6's with a stock .35 gap for those plugs. The thing is i wasnt running nitrous or a blower so why go colder? I dont know but I did. now i talked to my tuner, and he said not to run tr6's because it is more than likely making the cylinder run cooler, causing it to run rich. And when this happens, you have to run more timing, and that, that can create problems..

Well now that i was going to switch back, i found that I need a gasketed plug for my afr's!!

Afr reccomends a Ac Delco fr3ls, while tpis (who makes these heads out of afr castings) said to run a Bosch Platinum +4 (4419).

What should i use? and what should I gap them at?