Hi All. Just about to turn over my new 455" build. It's .030 over, Total Howard roller system (not too radical), 9:00 to 1 Icon Pistons/Eagle HBeam rods, Bernard Mondello re-worked Edelbrock heads, high volume pump, etc. Just a cruiser. Question is probably mundane but what Spark plugs should I use? I've heard a lot of good about NGK. Heat range? Any suggestions? Many thanks. Bill.

 

I have had good luck with regular old basic Autolites...yep Non exotic basic Autolites. Im running an 11:1, .030" over, 400 with a Stick 70 W30 spec bumpshaft and 8mm Taylor spiral core wires with a DUI 52K HEI. They wear nicely and preform well. Not sure on the cross-ref number but a good parts store will be able cross AC to Autolite. Dont like ACs. Never ran NGK in an Olds. Nor Champions. Only thing that gets Champions is what ever cant be crossed to another brand. Exception being Chrysler LA small blocks, 318 etc...
The number for the Autolites I'm using is... I THINK...AP86 or 75 (no AP prefix). Cant remember because Ive only changed them twice since 1986 but AP86 is more likely. The cross for AC44S is Autolite 75. AC,R45S=AP86, AC,45S=Autolite 76. But Id have a competent parts guy look it up if your interested in Autolites. I believe the AP86 is a step hotter than 44S...nicely confused yet? Ill check the car tonight if youd like.