The #4 spark plug could not be properly tightened with my long 5/9" socket that i used for the other plugs because the header pipe is in the way...is there some "special" socket/tool that will fit over the plug and clear the header pipe?

ITs a SOB I think i remember taking the rubber **** out of the socket slipping it over, it just barley fit. i cant remember if it was with or with out the wrench. some of them i had to put the plug socket on then use a wrench to tighten it.

I had a similar problem with my flowtech headers. I use a 1" offset box wrench with the one end cut off so it doesn't get in the way. I only use the wrench, no spark plug socket.

1/2" drive spark plug socket cut down really short. Use a box end wrench to tighten the spark plug.

What I use

1 3/8" drive spark plug socket
1 hacksaw
1 19mm offset wrench


Now remove the rubber from the socket. Cut the socket down in size so that it fits. Here is a trick most spark plugs (I use bosche supers) can have the tip (plug wire goes on) removed, it simply unscrews and screws back on, it will save you room to put the shortened socket on. Then tighten or loosen the spark plug as needed using the offset wrench instead of a ratchet.
Like what the guy above said.