Frankie, the thing with OS engines is that since it has such a humongous torque, the engine needs a pipe which enhances the mid and high end of the power band, and tht is where OS's own pipe excels, the other pipe which works well is the Mielke pipe, now regarding your question of which Nova pipe to use, i would go with the 2601 with 5 fin header...as for plugs, do yourself a favor and stay with OS's new rp6 or rp7, depending on nitro and weather conditions
Bye
AFM
cheers AFM - your info is very important, clear and staright the point, hence why i enjoy this forum for people like you "Thanks for the advice" i will decide in the next few days what pipe i go.... all depends on price!