Hello All, I have a 1968 340 in my Valiant and just installed a paxton supercharger

I’m pretty sure the RC12yc cross’s over to ngk 5 series. My BB Eddie heads recommended the 12yc plugs too, I am also running one cooler ngk 6 series. I’d have to go look but I think they are ngk-br6e? Or 6es?
Let me know if you want me to go to the shop to get the part number.