Hi Vev, the new 7/16 thru bolts do not use the 12 point nut. It's a rather unusual nut. Approx half the height of the nut is round and the top half is hex. I have them on my J160. While the bigger thru-bolt is stronger, if detonation is the problem, this will make little difference, as Nev pointed out. We don't have sufficient hours on it to draw any conclusions so far. BTW I cannot see what difference it would make changing the standard hex nut to the multihex nuts on the 3/8 thru-bolts. Regards, Bob