Well I just switched from a 2bbl intake to a 4bbl and ran into some problems. First, the 1972 intake didn't cover the exhaust emmisions holes in the heads (1974) so I had some leaks. After drilling the holes and tapping them, I plugged them with set screws. That solved the exhaust leaks, but now I have a hesitation on take off (just rebuilt the carb) and I am putting out lots of whitish smoke out the exhaust. It doesn't smell oily, and it isn't water vapor. I am hoping some of the sealant I used around the intake ports is just burning off. I also put in a thrust plate in the oil pump, and that didn't raise the pressure much (3 psi). I guess the motor is tired, but tomorrow is another day.
i believe that white smoke is coolant burning, might be causing your bog at off idle. otherwise bad float height or the accelerator pump on the carb might be causing an your bog. I'd solve the smoke issue first, is your water level in the rad lower?
Q-J Are you running a Quadrajet? I have the same problems with mine, but they stop as soon as the engine warms up. However, the carb has no choke. It has a big cam in it, and with no choke, keeping it running in cold weather is a royal pain in the rear. Also Mr. Teufert, I printed off some pics and the text story of your red 72 GS350 in the libarary of my school. Got in trouble looking at them in science class, and the teacher took them from me! Dammit. From Kevin
My hesitation turned out to be a dry rotted vacumn hose which leaked. A little more tweaking and it should be ok, except for the smoke, which is probably a bad seal on the water crossover. Visit here http://www.teufert.net/buick/engine/engine.htm to see how destroyed my original engine is!
