Spark plug for BBC Square Port Heads?

Engine: Gen VI 454 Magnum

Local speed shop set me up with NGK BR6FS plugs.

Does that sound right?

I gapped them at .40 thousands for use with MSD 7AL

They're going in kind of hard? Maybe due to some spray paint on threads on head when engine was painted?

I used autolite 105's and had the same problem, threads in the heads need a cleanup.

Grease up a tap and run it through, the grease will hold the small amount of crap you'll get.

Must be a problem with Gen VI heads.:cool: