Not to cold not to hot

[Cobraman]

So now that I have the carburetor all sorted out I'm trying to figure out what heat range of sparkplug to run. After some study it seems that one or two steps cooler than stock is recommended for my particular engine 500hp? 408 AFR185 heads 10.5:1 compression dual Plane manifold Pantronics distributor blaster coil ignition with matching wire's. So what heat range are all of you running.

[Mike.Bray]

I'm running NGK BKR6E in my 550 HP 393W and they seem to work well.

[BornWestUSA]

AFR says Autolite 3924 for those heads. I ran those last year. They were fine.

Now I have a set of NGK FR5 (7373) NGK "5's" are listed as the cross reference for the Autolite 3924

I thought I would try the V power NGK as I have always had zero issues with NGK plugs.

[cv2065]

Running AFR's recommended Autolite 3924.

[Cobraman]

OK that's what my findings were also always double check it just makes sense.