The AGPR12PP8 are std 4x4 yb plugs not had much in the way of testing on over standard yb's not a dis Tab !

The 071C's are also a std motorcraft plug but tested and reliable @ 400hp plus with no side affects then the next step IMHO would be denso irridiums but for value reliability and stats speaking for them self 071C's all day long .



Regards Doug .