I have two Wilson K6.1 95 using it more than 6 months and lately found out both racket are difference in head weight. One is lighter than the other one. Almost 1/4 drop on headsize when compare using a pen, from the throat hole (the edge at 7 o'clock). I took off the replacement grip as well but the butt cap and grommet on. I have gone thoroughly the racket, paintjob. No difference at all except I bought them seperately. Both racket is unstrung now. Should I add lead tape to the lighter handle to balance it. And is this common case to all rackets?