96 Vortec 305--Rough Idle and Smells Rich

[cris well]

Hi all.

I just bought a 96 Silverado 305 that runs great down the highway but idles rough and spits and sputters a bit at take-off but picks up shorty after with great power and it's not throwing any codes.

I also noticed that it smells really rich like a carb that is loading up at idle.

I changed the fuel filter and I was gonna check the fuel pressure next before I try anything else.

I'm thinking it may be a stopped up converter also. It has a small converter that looks like it may be aftermarket--I haven't looked at it too closely though.

Thanks for any info.