i`ve done it on me 172 cup, not really made much of a difference n cost a small fortune to fit!! but havin ITB`s fit at mo so should hopefully produce better airflow wiv the throttle boddies.
ur`s is a 172?? surely u wud be better gettin a d-cat pipe from k-tec which will allow u 2 fit a 182 manifold to a 172 exhaust cause thats what i hav, surely fitting a 182 cat won`t fit the normal 172 exhaust or uprated exhaust (unless you r gettin a 182 exhaust obviously) well thats the impression i got when i ordered mine. fred??