bro, im driving suzuki sj410 with g13ba 1.3 engine auto,

want ask u,which 1 better extractor 421 or 4to1 ??i want for torque within low to med rpm range and bit of bass sound,..any recommend? and can recommend me the full setup if can,from extractor til muffler, which 1 better,..

pm me the ur recommend and product, might buying from u..tqtq keep up the good work..