I am building a 10 to 1 489 BBC with Brodix race rite oval port heads. The roller cam will have 229/235 duration at 0.050". This will be in a street driven 84 Cutlass. Brodix recommends an NGK R5671A-7 racing plug. I don't need a racing plug. I do need a plug with 14mm threads, 3/4" reach, gasketed seat and 5/8" hex. I like autolites but am not sure what heat range to start out with. Can anyone help me pick out a plug for this engine with a good heat range to start with? Open to all plug brands.