Ever since I replaced the stock plugs Ive needed to tighten them about every 1000 miles, has anyone else had this problem?

 

There's a thread about this over on webbmotorsports.com - in the performance mods section. And yeah, I check my Densos from time to time and I usually need to tighten one or more plugs.

 

Are you re-torquing the plugs when they're cold? As in, overnight-since-the-engine-was-last started cold?

Otherwise you usually can't get an accurate reading due to the aluminium head and the way they handle heat/cool cycles.