what plug
I use this head with 11.5:1 comp, race gas, and a -7 NGK. 200hp jetting and it's great. Will it work with pump gas? Probably but I like to keep it way over on the safe side of things.
On motor, he could run NGK's FR5 plug. I might be ok to use with a 150 shot if you can't get the -7 stuff but I like to reccomend the non-projected tip plugs(like the -7 thru -11) for nitrous. It's what the big boys swear by.
The COLDEST plug they make is a -11... it's what you would use in a 2500hp 5 stage nitrous Pro Mod setup. Might not work so well in a 10:1 355.
Goodluck!
download the excel matrix, has cross reference of everything,
will make it easier when you go to the parts store, you can give them the plug stock #.



