Originally Posted by tnoftsger
I had an old Ford P/u that did that....Turned out to be a cracked rubber fuel line from the tank to the frame rail. When the frame twisted the crack would open and break the suction from the block mounted fuel pump. If you didn't hurry up around the corner it would begin to stumble lean.
Since a carb swap didn't help i would look for a fuel source problem. Of course a loose wire in the ignition could be doing the same thing.
I hope this helps you at least with ideas.
Well I have a holley blue inline pump on it w/new line from the top of the tank all the way to the regulator and carb.. even have two filters on it... But I'll check anyways, never considered the ignition wire but I would think it would have to be the 12v wire to the distributor to cause that and that wire is good... hmmmm