ummm. Check Wires? did you remove them? if not thats not it. If all you did was swap trasmissions that is a really weird issue. It should not change anything to do with fuel misture or air mixture. but fouled plugs.. hmm do they smell like Gas like strong gas or is it oil.?? Gas could be the reason the Front of Cat is red because fuel is detonating in the exhaust itself.... that could also be a plugged Cat but you said its not right? tryign to think of where at work I saw this before... ummmmmmm

 

update: i had a little time to work on the 280. So i replaced the plugs and wires and replaced the coil, d-cap and rotor button, no help at all. fired up but running just the same ( like $#!&)
It seems like it is developing a pattern, it will crank up after it sits for a days or so, runs decent for like the high idle period when you crank a cold car up. when you first crank it up you can work the throttle "pretty smooth" (not perfect) from idle to about 3-4 grand and it responds decent. but with a noticeable miss. After about 2mins of running then it goes straight to the pits and it sounds like the plugs are fouling out. And dies. Then it wont crank until i clean the plugs or it sits for another day.

all help is much appreciated
Jason

 

check timing? is your distributor shaft sloppy? Have you checked ALL your sensors and the TPS to make sure its not nasty inside? Get another AFM from ebay or the junkyard and try that too. Spares seem to be the best way to diagnose stuff on these cars. Usually when the exhaust glows and tries to fall off thats timing, but it sounds like yours only glowed after the cat Did you have any of it off for the trans swap?