Adding Catalytic Convertors to the Old Girl...

I smelled a old chevy truck going by, 4 houses away. that thing stunk of raw fuel in a way that I thought was not possible. If you can tune the carb, there will be no noticeable smell. Its very easy to see with a wideband, narrow band not so much but even a narrow band will get you stoich at idle. 1/8 turn of the metering screw can be the difference between a stinky exhaust and a 'clean' exhaust. Cats run hot, so hot that some had shields under them to prevent brush fires. They make high flow cats but without the supporting hardware, I dont think they would be worth it. You can run a pulse injection setup into the exhaust manifold like my mazda. Its just a beveled pipe in the exhaust manifold that is open to air cleaner air, and it flows through a big rubber flap one way valve so a backfire wont blow your air cleaner lid off. It provides the exhaust with O2 so it can burn off unburned hydrocarbons in the manifold. A.I.R rail off a later 360 will do the same, and look cleaner too, no smog pump needed, just run through the check valve.