Hey JB,
you're getting mellow in your old age /ubbthreads/images/graemlins/smile.gif I can remember the time ..... ahhh , nevermind /ubbthreads/images/graemlins/laugh.gif
GM Top engine cleaner sells for about 6 or 7 bucks a QUART . It will remove carbon as well as copper, Butches Bore Shine is the same makeup as GM TEC with the addition of some color and smell. I have used them both back to back , front to front , sideways ( I'm getting crazy here )and they are identical in performance. So , the big difference is that Butches cost twice as much as the GM TEC.Oh, yeah , the GM TEC comes in a nice , sturdy METAL can , the Butches in a glass bottle that has a crappy top/lid /ubbthreads/images/graemlins/tongue.gif
As far as the "others" go I have used them and gave them away( some of them pretty expensive)The only other cleaner that I use /have is Barnes CR10 , it will get a little more copper after the GM TEC but that is only if you rush the GM TEC. /ubbthreads/images/graemlins/cool.gif
Jim Brown