4-into-4 exhausts 1993 CB750 Nighthawk

[Darkwing]

My 1993 manufactured CB750 Nighthawk has the standard 4-into-1 exhaust. I would like to change this to 4-into-4 system. Anybody have any experience of doing this? Any information will be appreciated. The Nighthawk was a California registered version which I brought back with me to the U.K.