when you see shorty headers and the pipes look all curly, those pipes are all the same length, unequal length headers have the pipes going from the head straight down to the collector, long from the front short in the back...
Do a search for lots of info, this has been discussed plenty of times
The most power and TQ is with the longtubes. It cost about the same to do a longtube header and short mid pipe as it does a shortie header and long midpipe. Some classes of racing do not alow longtubes, and they have thier problems with emmisions and clearance issues especailly with auto trannies. That is why shorties are made, not because they have any advantages.