I am located in the Marietta/Kennesaw area which are suburbs of Atlanta!

 

I think you need to replace "is" with "should have been" in the last sentence. From what people have found with these engines, many of the liners never made it to the bottom of the bore. Nice quality control. All of the pictures I have seen of blocks with slipped sleeves show the top of the liner sitting below the top of the block. Once the engine overheats, the liners finally seat against the botom of the bore.

 

There are also a number of salvage yards in Atlanta where a used engine will be cheap, but an unknown quantity. It will need a head gasket job as a minimum usually. Certainly with driving distance of Wade Green Road.

 

I'm dying here. I have been clicking and calling for two solid days trying to find a used engine with some reasonable level of miles. Roverlandparts wont have one for several more weeks. It seems like the most reasonable way to go that I have heard thus far at around $3,250 for an engine that they check out. Other than that I cannot find anything. How in the world does one go about finding this needle in a haystack (4.6L w/ secondary air) with less than 60k miles? Almost everything I find is around 100k miles. I am about to give up.

 

Perhaps you should consider just head gaskets for yours, a test can be done during that work to confirm if block is leaking (they block off passages and pressureize it). With low miles, these vehicles are a rebuildable wreck. In may wrecks, they come out on top (knock that Volvo to next week).