maybe Gibson didn't and someone else has altered them, they look like they were made this way, I have other Gibson pipes which exit either side but all look to be original welds on all pipes, they seem to perform well, I have not tested back to back with anything else, another job to do on the dyno when I have time.
Pete Gibson did alot of "one off" designs aswell as the mainstream setups,ive seen 4 different sets of pipes he made for the KR1 and S.
Great pipes they were that he made,for some reason some of the pipes under the Gibson banner dont seem quite the same as they were,its noticeable in the header section,wether they work aswell as those Pete made i dont know.