Catalytic Converters For Vintage Muscle Cars...

[Filthy Filbert]

On the flip side, my 98 dakota running the factory computer and EFI system, retuned for a lumpy cam, is running without a cat.  Because the tune is spot on, there is no "raw gas smell" from the exhaust.  If your exhaust makes your eyes water, then your carb needs work.   Use a wideband O2 sensor to dial in your carb, and use a data logger to monitor air fuel ratios across all the conditions the engine will see.  Idle, part throttle cruise at various RPM and engine loading, WOT, etc.   most folks put forth a minimum effort to tune their carb.  Turn the idle mixture screws a bit here or there, change the jets for golden brown spark plug ceramics at WOT, done.