As this is my first post let me start by saying I'm only posting because I've researched this issue for the past 2 weeks with no solution
Rewind back a few weeks ago I found out I had the famous castech head failure . So I went ahead and replaced both of the heads valves gaskets etc. Put it all back together only now to have my truck idle about 100rpm lower than before(about 540 now).
now what I've tried to correct this issue is replace MAF, o2 b1s1 that was throwing a code, ran vacuum tests and found a few minor leaks that have been taken care of, checked fuel pressure. static pressure 54psi and running sits at 60 idling. I've also cleaned the throttle body and reset the system and replaced the battery. None of these have made a difference.
I'm about at my wits end on what to do so any input here id really appreciate

 

Welcome Cam - how's it running/driving? I don't know idle spec for the '04, but our 5.7 '93 idles around 500, ans so does our 5.3 '21

 

thank you
I don't know for sure the spec, i haven't come across it in my Hanes manual yet but from reading forums I've got a mix of people that say 575 at temp and other say between 600-700 at temp
before the head job it never dropped below 650 and now with it around mid 500s the only real issue i have with it is occasional weak power steering
as far as driving goes it runs and drives great. After the work was done i also had issues with the low idle( i would assume) causing low oil pressure and smelled lean but quickly found out it was bad plug wires and replaced those and changed oil again solved those.
Its worth mentioning i had 706 heads and the new heads are 862. i assumed removing the neg battery terminal would reset the system but maybe I've missed a reset procedure