Hey guys I'm headed to Napa in a few minutes and wanted to know the nut size for the adjusters found on my rocker assembly. I want to buy that nifty little valve adjustment tool. Is it a 17mm??? 1978 2F engine. ADDED LATER: who sells these wrenches with the crewdriver thingy on them, Napa no longer sells them in my location. any advice on a decent vendor? I don't need super snapon quality and price as I do one of these a year at max.