I have a 4.3 V6 with an ebay Rochester 2GC carb on top. For the most part it runs quite well. It has good idle characteristics and has decent power at full throttle. The problem that it seems to have is when I am at moderately low RPM in high gear (using engines torque more than HP), and am slowly accelerating, the engine will occasionally pop through the carb and then immediately start pulling again like nothing happened. If I give it a little more gas after this happens the power starts to drop off until the RPM comes up a little, then it accelerates like normal. It almost acts like it is going lean during this time, but this carb should have came jetted too rich if anything (supposedly calibrated for 350). I have also wondered if there may be too much vacuum advance, but I would have thought I would have seen signs of knock if that was the case. The underhood temperatures are fairly cool and I don't have any hot restart issues, so I don't think vapor lock is an issue. What do you guys think?