Looking for some suggestions on how / where to mount this thing. I have a 401 with the stock manifolds and the air injection smog crap. I'm installing TBI off a GM 454 and need to install the O2 sensor. Ideally I'd just tap the manifold and screw it in, but the walls are too thin. I'm tempted to pick up a piece of scrap cast steel and weld it to the manifold as a boss and tap that, but thought I'd look for other ideas first. I prefer mounting it in the manifold because it eliminates a possible exhaust leak before the sensor (the gasket between the pipe and the manifold... that sucker always seems to leak for me <IMG SRC="smilies/rolleyes.gif" border="0"> ). I see a couple alternatives, one being just welding a nut to the pipe and installing the sensor there (which brings into play that possible leak), or ditching the cast manifolds and buying headers and welding the nut on the header (do any AMC V-8 headers come with O2 sensor mounts?). Waddaya think, how/where would you (or have you) mounted an O2 sensor?