o.s 18 is nice, the wasp 12 revsis like a right little devil, great for drifting and also the orion screams at 41,000rpm!!!!!!!!

that is the way i would be going, A5 are good plugs and good in most weathers, i would only ever.. if i had to, lol, put one on a big block, 28+ engine!!

towers is good, check them out, there are like a million sites, typer in google...lol