First off, I'm new here, and I've learned quite a bit by reading this forum. Mostly bad things, but all learning is good. I've got an '83 Jimmy that rolled out of the factory with a 305, but had a 350 swapped into it at some point. It was running real rough, so I replaced the cap, rotor, wires, and plugs, as well as the fuel pump (which emitted a black goo when removed) and fuel filter (no goo, but it was no longer a paper cylinder, but a ball). The carb is the original from the 305...I'm doing the timing in the AM, but I've already convinced myself that it won't help. My question is - is there any issue using the carb that was not tuned to the 350? As it appears that the fuel filter was being sucked into the quadrajet, I figured it might be a good question... "Oil? That's not my oil...that was there before"