Check my thread on 4.0 SOHC head gaskets last fall to see my debacle with remanufactured heads. I bought two sets, one from a "machine shop" on eBay and a set of LKQ heads from Autozone. All 4 heads arrived with issues. Leaking valves, gouged gasket surfaces, destroyed camshaft journals and the set off eBay had two right side camshafts in it so they both used right hand threaded cam sprocket bolts lol.
I'd avoid remanned heads or engines like the plague. Others warned me but I was in a rush and didn't want to wait for a local shop to rebuild my heads which I was forced to do anyway after wasting a bunch of time ordering and returning junk heads. I had mine fully rebuilt by a reputable local engine builder in less than two weeks and they came back perfect. That's my advice to you and save yourself the headache.
