Is it a worth while upgrade on a 172?
Only if for another reason the engine is out or subframe dropped.
Im currently in the middle of doing mine, i spoke to k-tec at autosport and they say with a decat and their matched inlets it makes a worthwhile difference. I've also got the subframe off anyways for a sump replacement and new gaskets, so it made sense to do it all at once, also makes it alot easier to switch between decat and cat for mots
Well, I did the manifold swap, can't say I noticed any difference but figured that every little counts when tuning NA!