I bought a set of assembled EQ heads back around 2016. Went to their place in Chicago and got the last one from one pallet and the 1st from another pallet, for my 01 Durango 360.
I had a fresh engine, and I trusted the "ready to run out of the box" and it cost me dearly.
That motor had all of 3 hours on it and I didn't make it 6 miles on the maiden voyage and I had to call my kid and a tow strap because of them. I ruined a fresh build because of them. Back then I paid $700 for a set of brand new assembled heads and bolted them on. #4 exhaust valve stuck and met a piston.
And $250 more, to a machine shop to straighten them out. The guy said he had had several engines over the years that had sat in damp places and had valves stuck from it that he didn't have to work as hard to get valves out of as he had to on this set/ especially the intakes. And he went in and on about out of round valve seats that took way too much work to "square up".