why did you change your intake? are you running the same carb? do you have a good quality fuel filter? did the gas that you drained seem different from the new gas that you put in? oder, doesnt evaporate fast, weird color? could you have left a rag in the intake? have you pulled the spark plugs out and see if they look differet from each other?
previous intake had a bad water jacket, im using the same carburator., the fuel filter has been replaced. no reg left in the intake and the gas was from cheap gas station so i decided to swap it out. i know one i put some bad gas in my caddy and it wont go over 30 mph. spark plugs were all replace with platinum plugs
cap and rotor were both replaced when the intake was all new.... it ran fine untill i had to get gas.... crazist thing
the bad gas could have fouled some of the spark plugs. platnum plugs are only good for longetvity. regular copper plugs like autolites will give you beter performance and economy. they also have a larger eletrode that is harder to foul. pull you plugs and see how they look when compared to each other.
Poor engine can't power those rims around! LOL Kidding! Sounds like a vacuum problem! Either that or you could disconnect the fuel line and blow some air through it!