Kavesh, spray some carb cleaner around the throttle shaft while the engine is running; if the idle speed increases then you have a vacuum leak around the shaft. As 70 Nova stated; the cam may be worn rendering unequal valve action cylinder to cylinder, when you couple this with the poor distribution in the stock manifold you can get a lean miss. You might also check the timing gears; Pull the distributor cap so you can view the rotor.....turn the engine counterclockwise about 1/4 turn.....mark the dampner at t.d.c.....turn the engine clockwise(normal rotation) untill the rotor just starts to move, mark the dampner at t.d.c. again.... the distance between the two points is the gear wear.Calculate the circumference of the dampner and divide that into 360....that will give you the degrees per inch....everybody has their own cutoff point but 6 degrees is what I consider absolute max on stock engines;even though the ignition timing is adjustable in relation to the crank, the valve action is not in sync. with t.d.c. and performance suffers. fats
