Im almost at the point of getting a honda!

Lets just say that there is a 360 out there that was rebuilt about 7000 miles ago. It ran great, idled great, no problems at all...until one day it started to run like crap. When you first start the motor in the morning it fires right away, warms up to 180* you bump the throttle to drop the idle and away you go. About 10 min. later it starts to run rough, theres a low miss through the exhaust, you have to power brake it to keep it from dieing.
Back in the driveway you put it in park and it smoothes out, you give it some gas and right off idle it starts to sputter and backfires out the exhaust with a loud crack, unhook the vacume advance, give it the same amount of gas and nothing. It reves fine until about 2500 rpm then it starts to cut out and sputter, rev it higher and it smoothes out but there is still a little sputtering.
if you do a quick rev from idle to say 2500 rpm as soon as it drops back down to idle it runs rough, slowly bring up the idle and its rough all the way. Shut off the car and start it again and it will idle fine. With the idle adjustment screw 1 1/2 turns in like usual there is now 5lbs of vacume comming out of the pass side port on the eddy carb (2 diferent carbs, one was brand new). If you cover the carb with your hands the idle drops and the car will die.

Now lets say that the fuel system from the tank to the carb is fine, the charging system is fine, the ignition system from the pluggs to the box is all fine and all the wireing under hood is fine as well. There is no oil in the water or water in the oil, the temp stays right were it should be and the oil pressure is great.

You have tried

2 different carbs (one was freash out of the box)
4 distributers
2 sets of new plugs
new wires
2 caps
2 rotors
2 ign. boxes
new fuel pump and filter
new ballast
new voltage reg
new alt.
new intake gaskets (cam looked fine when intake was off)
new carb base gaskets
doucheing the hell out of everything with carb cleaner, propaine, and wd40 looking for vacume leaks and found nothing.
there is no water in the gas.


What would your guess be? Internally what could cause a motor with all new gutts do this? Vacume leak, where?