What NGK spark plugs for a 10.5:1 451?

Looking to try something different from the Champion RJ12YC's. Using OOTB Eddy heads, 10.5:1, solid cam 254/.520, 1 7/8 Hookers, 800 Eddy carb, MP electronic ignition. Appreciate any suggestions.

i have a similar combo, was looking for other options, too...

Why would you use a RJ12YC plug in an Edelbrock head? Those plugs don't even fit that head.

i think he meant rc12yc...

Why are you looking for a different plug? What do the plugs look like now?

RC12YC is correct, these have been in there since I broke the cam in and have ran it a few miles, these were recommended from the literature with the Eddy heads and just looking for something else that might match the overall combo a little better. They appear to be firing OK though.

If they look ok I wouldn't change them and if they not I would change to another champion, it will be a lot easier to change to a hotter or colder plug within a brand that it will be changing brands. Call Champion, Federul Mongol, they have a great tech guy that will tell you more about plugs than you could imagine.


Ken

I tried to peek at the number on the NGK's in my 383's Edelbrock heads but couldn't see it, put them in years ago so I don't remember.

For street use......FR5's will do with the Eddy heads.
They are just a tad cooler than RC12yc's and because they're an NGK they WILL work good!