Here I am. Sorry been out of pocket. With regards to the backfire it is through the exhaust. I put on a fuel pressure gauge and it runs about 5lbs. The sychro I used is from edlebrock. The timing is on the "ball".
I still have the same prob. The truck will run fine for a while but then it will start burbling and backfire thru the exhaust and then run a low rpm at idle about 300 to 400 and just run rough at Idle. I've tried to duplicate the symptom and I think it is after a high vacuume event like down shifting. You can blip the throttle and the motor will spool up fine but then drop back down to low rough idle. I have even seen it run low and rough and then slowly creep back up to a normal idle about 600 to 800 and smooth out.
I've hooked up a vaccume gauge but I must have it in the wrong place. The port above the throttle plate where I have the vac advance reads 0 at idle but reacts with a flip of the throttle. The ports below the throttle plate react the same, 0 vac at idle but reacts with a flip of the throttle. It's the same on both carbs.
I am totaly baffled.
Rick.....
