If that guy is charging you 5k to remove/reinstall and rebuild the motor (completely-which means the required machine work,new parts,etc) that's not a complete raping(still probably overcharging).
That motor wouldn't go back into my car without the following:
Hot tank/magnaflux the block. Also minimum it will need to have cylinders honed(needs to be checked-probably bored). Check the deck for straightness,align hone,new freeze plugs,cam bearings,and chit I am forgetting. A cyl bore is going to require new Pistons and rings. The rods will need to be checked and probably resized with new bolts and bearings. The crank needs at least that much tlc. You'll also need new oil pump,shaft,gaskets,water pump,lifters(and cam),and again misc crap I'm not thinking about.
Then the heads....for as much machine work that you're going to probably need, there is no f'ing way they would go back on my car. I did that same thing years ago and have regretted it every day since. The stock heads are such pieces of chit for performance. They absolutely suck. At least go with some gt40's of the explorers. Check the local junkyard/parts places around town or check the Internet. You can find them on eBay or you can check the parts section in the classifieds on Corral.net. Usually can find them already setup for around 500$ or better yet buy some Trick Flow 170cc heads(1150$ brand new). I'm to tired to continue. And btw I'm 15 miles away in Byron,Il