Sparkin Plugs
 

Wondering if ya'll have suggestions for plugs for me. Working on a couple of SBC new builds. What is the best way to determine what plugs to use? Planning on doing a dyno tune to one of them, but not sure when I can afford (or if yet) the dyno, plus, I should show up with some plugs. I know how to watch the plugs and what to look for, but where do I start? (without buying and trying)
406 3.750 strk/6" oliver rod/1.125 comp ht with SRP domes/13:1 to 14:1 compression/dart 220s,angle plug-58cc/super vic/holley 850/110 or C12 gas/circle track asphalt, all on a sesame seed bun.
Help would be appreciated, guessing to try (if I have to buy and try) Autolite AR131 cold
through
AR135 HOT

NGK R5671-7 or 8 or 9 (hotter to colder) will get you close. Go 8 or 9 with iron heads, they have 10 and 11 for boosted or heavy NOS.