I usually went with the factory plugs.
Go to a local parts store and ask them to pull several plugs for the same application and compare them.
It will surprise you how different they are.
Plugs are sold based on thread and heat range, not the position of the electrode in the cylinder.
Also the AC plugs are probably stainless for the marine application. Wait until after a couple of years and try to take the non stainless ones out.
Never fouled a NGK plug. Have fouled some AC. Put some anti seize on the threads no problem coming out
Just installed AC Platium in my 496Mag HO's. They seem to be fine.
AutoZone has a $2 rebate per plug. $32 back at $7.95 each. Not too bad. Plus I am a rewards member, so an additional $20 store credit!
Dave
Yep, 41-983 Platinum is what I did. Also, my buddy says that Raylar (the 496 guru) recommends to gap at .050 not the book gap of .060.
Again, I followed that advice and things are running smoothly!
Dave