Read my plugs.

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aaronk785

aaronk785

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This is a plug I just installed and removed after a test run. Test drive was about 16 miles at highway speed (60) and 4 wot runs through all three gears. Engine is a 408 10 to 1 comp. Solid cam 254 260 at .050 .565. .570 lift. Home ported speedmaster heads. 4500 stall 3.91 gears. Looks lean to me but I’m no expert. Oh. Preform 750 do 72 78 jets.

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What plug and heat range? I’m assuming pump gas.

I can’t see any fuel on those plugs. Have you verified the size of the main air bleed and the emulsion stack?
 
I don't see anything to speak of. Maybe it is the lighting or the picture quality. I am not sure if 16 miles is enough to see much of a problem that will show up in a cell phone internet picture.
 
What are you trying to learn from reading your plug? If it’s wot fuel, you need to not idle around and drive on it. Just make a pass and click off the ignition, then look at the fuel ring (cut the plug to really see it or get a plug viewer). Timing? Looks a few degrees light to me. I’d guess for best power you’d need two more degrees in it. Heat range? I’d say one or two ranges to hot. No color in the base or threads. Idle and cruise fuel? You’re probably not far off and relatively lean. Might fatten it up a skosh.
 
The timing mark is about at the bend, to confirm back it up 2 degs and make a run, then add 2 degs at a time until it drops mph. Then you can take out 1-2 degrees. Using the ground strap for timing can be misleading if your plug heat range is off significantly. That plug shows no heat in the threads, but could be because of limited run time. I like to cut the crimp on the plug and pull the porcelain out.
 
Plugs are ngk no.6. Have to check on MABs and emulsion jets. Been busy so haven’t been in the garage lately. Plus it’s cold and rainy. Thanks for all the advice. I’ll be back when I get more details for you. Timing is 20 initial and 32 total.
 
Looks like light Tan on the strap to me so you're in the ballpark.
 
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