I wouldn't use a cold plug in any car engine unless you're running 30%+ nitro. Hot or medium plugs are the ticket. I use hot plugs with 20% nitro; McCoy MC59 or Enya #3 are good ones. OS plugs are a ripoff

I like to have several spare plugs on hand, so if it were me, I'd have 2 or 3 on hand. It sucks being out bashing and have a plug burn out and not have a spare.