Spark plug question

4spdragtop said

So the FSM calls for Champion N10Y for 273 4bl(commando), 273 2bl is Champion N14Y. Our engine has 2 bl pistons, but 4bl carb/intake, 340 solid cam.
Currently I have new Autolite 66, which cross over to Champion N14Y.
Is there much difference between the 2? Benefits to switching to N10Y?
Handy cross reference site
spark plug cross reference
Thanks
Steve

Click to expand...

Probably not but like TMM said, the crossover is a somewhat close approximation.

FWIW, any of the above Champion plugs can be had with a 5/8 hex and not that clunky 13/16. The plug is the exact same other than the hex. I just hate that big hex.

Always let the plug tell you if your heat range is correct. If the plug has a black shell its much harder to tell heat range.