Thundergod, TR5IX are the same heat range as the stock plugs, be careful as I fried two of thm on my HD last year...I just installed the TR6's today, gapped at .038.
I was pleased to see that all the stock plugs had the same gap at .044 and didn't look too bad...w/4# lower and SCT.
TR-5IX's here, but I am still running stock pulleys. I am upgrading to the TR-6IX's this weekend while my L is in pieces in the garage.
Started getting the telltale spark plug tick so thought I would change them, then decided it was easier to change with the supercharger off so I could clean my intercooler...BLAH
RhinoHD, good information on the plug gapping, that is a handy range remember.
Lightning Mike, those look to be OK, I think the AR-103's are the equivalent of the TR-6 if I remember correctly. Running rich isn't necessarily a bad thing unless you are too rich, then you are more likely to foul a plug and lose HP. Best bet is to dyno it after you install all the goodies, then you can check the A/F and dial it in.