So please excuse the noobie question, I am still learning more about cams (and other things). In the Vizard book I am reading, he is a proponent of single pattern cams (particularly for street type applications). As I am browsing cam companies' catalogs I see that pretty much all off-the-shelf cams are dual pattern (at least for hyd roller "street" cams I am looking at). Is there some reason that I don't see any single pattern cams? I am sure this is not a question that can be answered easily, but maybe the more relevant question is why would someone choose single over dual (or vice versa)? From my catalog browsing, it seems like the cams that would be most appropriate for my build have 6-8* more exhaust duration @ 0.050. I know I can get any cam grind that I'd want, so mostly curious why all I see in the catalogs are dual pattern. Thanks for helping me better understand all this!