Not suggesting that the folks don't do a good job, but years ago we used to
have occasion to send several radiators to be rodded over the course of a
couple years.  Every time we picked one up, we asked the guy how bad they
were, and every time the answer was, "Oh, about 75% blockage".  Kinda makes
you wonder.

Karl Wolz

I haven't
had a chance to use the injectors yet but they do come with a nice graph
showing before and after flows.  One was completely plugged!

Ken Wilford