Ford Repair: Mustang cat glowing, engine running rough, double pumper, cylinder pressure

Question
I started having issues with my Mustang 5.0 1985 carb, 5sp lately.  The engine started hestating and idle would surge from high to low, it also smelled of gas strongly.  I took it in and they said they found some leaks in the carb and fixed by tightening.  I have had the module replaced 2 years ago, carb rebuilt 2 times, mostly due to the module recall.  once that was replaced it ran fine.  So, while trying to trouble shoot I look and seen the cat glowing red hot.  I had it replaced and it still will start fine but after getting warm it will glow and then the engine starts to pop and run rough.  The popping is in the exhaust.  The mech, says it is the carb, one bank is running lean and needs to be adjusted but the carb has no adjustments.  He says replace it and it will fix.  The past mech, said the smog pump should be bypassed.  What can i do to determine cause of glowing cat and engine running rough?  I did recently (2 years old) swap the orginal exhaust from a 2 into 1 into 2 to a true dual exhaust with 2 cats and H pipe etc. After replacing the cat the same one is glowing the original side if that helps.

Answer
Anthony-

  A glowing red exhaust is almost always a sure sign of a lean running motor.  The increased cylinder pressure makes the exhaust super hot which, in turn, makes the exhaust glow.  If you're still using the factory Motorcraft carb, I'd just ditch it in favor of something like a Holley 600cfm double pumper.  They're more reliable, can be adjusted pretty easily, and you'll probably even pick up a little performance.  Hope this helps.

Steve