i bought it 7 yrs ago it came with MIG high mount exhuast, not sure as to what jets are in the carbs . no i did not get iridum plugs, just stock replacment NGKs. left them gaped they way they came, just made sure they werent smashed flat. no special air filter, still has factory air box.
i have noticed that the surge is starting to come on around 2800 rpms and going away around 4100-4300 rpms.