advice on spark plugs

[88stanggonebad]

what would be the best spark plug to use on my 351w with 10.1 compression, stock heads, 270h cam a stealth intake and a 625 carb. currently im running autolite 25 with .035gap. i took plug #1 and it is powdery black ill try to take some pics.forgot to mention i have the pentronix ignition system.

 

[2bav8]

That's a good plug...
Just need to lean the carb down a tad.

 

[88stanggonebad]

on carter carbs, how would i lean it down a tad?

 

[2bav8]

With a Carter, either smaller primary jets or bigger metering rod.