99 c2500 hard start and rough idle ....HELP!

[n8zdogg]

Here's the description and details of what's happening:
99 c 2500 dually, 7.4 454 vortec
Replaced:
Fuel pump and filter
cap, rotor, plugs
3 fuel injectors (dealer cost about $700) --its still not fixed guys!

Symptoms:
At cold start it will blow black smoke on start up and miss on idle
Once hot (warmed up) it has to be cranked about 15 seconds or more if it will start at all until cooling back off. Then same rough idle. It also does seem to have some power loss (cats clogging due to rich condition?)

I've read several threads here about the Fuel pressure regulator, but not on this particular truck/motor -- as always any help is appreciated.

[n8zdogg]

Even though there were no responses to my thread, I went ahead with the Fuel Pressure Regulator change. The problem seems to be fixed.

I would still like to ask if anyone has any ideas on whether or not the cats could be clogged from running rich when the FPR was bad?