Champion RJ12Y's forever in all mine, B's and RB's. I've got new ones for my 440 Source heads, forget what they are (whatever was recommended, after market heads are DIFFERENT!). Quickbird has NGK's in his new build of the real big, big block. It's actually running now after last weekend. It WILL be at the Columbus GG show and the MOPAR NATS (needs tons more work). He needs to work on it instead of running off to party for the Memorial Day weekend. Mine will be together before too much longer. Too many events getting in the way!