how much raw gas will ruin a catalytic converter on 1997 Chevrolet 1500 Pickup

replaced distributer cap with high performance cap and it caused the truck to run poorly missing really bad and you could smell gas

2 answers
Why did you replace the dist. cap to start with? Are you SURE the plug wires are back on in the proper sequence now? Check engine light on?
distributer cap you replaced might also be bad, it happens.