I have a 01 QC with the 4.7L with 112k. While driving to the in-laws 150 miles away from where I live, I noticed that when i let off the gas the Oil pressure doesnt drop off like it usually did... I thought nothing of it, until 3 days later when i noticed it was still showing max pressure at idle... It does flexuate a little but it stays between max and 7/8th from max even at idle...any thoughts? no noises, leaks, no evidence of burning oil, no noticable loss of power, nothing stands out that could cause this...

 

My first thought would be to replace the pressure sending unit. Or, at least temporarily install an actual direct reading gauge to see the actual PSI readings.
Allowable pressures are as follows: curb idle for the 4.7L should be at least 4PSI, and at 3,000RPM should be 25-110PSI.

If that doesn't fix it, try changing the oil and filter, and pay special attention to the old oil.

In the off chance it isn't one of these two, most likely the oil pump pressure relief valve is bad (not opening up to bypass extra pressure back into the pan), or you've got blockage somewhere causing back-pressure in the system.