I went from a 1 7/8 Hedman Hussler race header to the TTI 1 5/8 to 1 3/4 step header on my stroker small block and have had better performance. I'm not hip to all of the science that Rat Bastid mentioned above (that stuff is just voodoo magic to me) all I know is I didn't lose any performance. Now, I will say I had to play with carb jetting to find the happy spot, which could point to some of what he was speaking about.
