That's what I've been hearing. But the only one who has said they were using them in a SB has been S/6 Dan... just would like to hear from someone else about them.
whats it matter? they are a good plug for a mild to hottish build. with the extended tip you get a better flame front due to the tip being into the chamebr farther, a compression bump, and a NGK. try it and it you like it great, if not go back to whatever the norm is, but im willing to bet it loves it so long as the piston dosn't hit it