Restrictive Mufflers

67 Dart, I should have that article. I am pretty sure it was David Vizard's 70's article where he fixed up a cat. conv. for a Monza and also tested some mufflers at the same time.
I'll try to get it for you and post it.

UPDATE: 67, I went through my stuff and found all the way back to the 1973 Hot Rod muffler test. I also found the Vizard article about converters but it was not the one I remembered. You know, we mad a single system for the wagon and tested lots of mufflers on it; could that have been the one you are remembering?

Tom