I have a newly built sbc350 with a 700r tans. Installed a Holley 750 double pumper. Probably too much carb but it seems to be working just fine for now. engine starts right up and idles great. The engine actually runs real smooth until about a 45-50 mph cruise. Then I sense a slight sluggishness, or stuttering. If I accelerate it goes away. If I take my foot off the gas it goes away. Is my timing off? It doesn't really seem to be. Is my carb out of adjustment. I did mess with one of the pump adjustment screw on the carb, but not too much. Could it be a spark plug or crappy wires? I have never ran a sbc350 before so I am not real sure what the power band should feel like. I do not sense a huge amount of power. It seems to me that a sbf302 produces more power, but I guess i could be wrong.