I have a 2000.5 chevy 2500 with the 6.0 in it, and it has has strarted ilding rough and startin hard after it gets warmed up. it will ususally start easy when it has sat all night but other than that it statrs hard. It doesnt act like a spark issue(plugs or wires) as the tach does not show any movement at idle, oh and it idles at 500rpm. it seems like a fuel issue, but the fuel pump was recently replaced. Any ideas?

Sounds like an FPR

Yes, fuel pressure regulator. Very common on the 6.0.

pull the vaccuum hose of the regulator,,,,,, if you smell gas, or it may even be wet.

That is your problem

intake leak?

Where is the fpr located at?