As you know they need replaced or beaded. I use one of those mini plug cleaners with shop air & fine black abrasive (forget what type it(the abrasive) is) & it works great & makes em look like new. The ground strap tells the heat range & the flat on the threaded end tells the AF ratio rather than the insulator as commonly thought but I might be wrong on that. Google it & there are some very comprehensive sites w pics for this which'll tide you over till you spring for the innovate LM1. You ain't running too hot nor carbon or oil fouled so I'd say you're in the ballpark. EDIT found it: www.wallaceracing.com & scroll down to the "plug reading" article. pics & very informative