5 grand to rebuild a slant 6? That's with who doing the job? And with them doing the pull and install, or you? I did my own, had to farm out the machine work, I'd have to go back and do some figuring, but I know I'm not into mine for over about $1500-1700 with about 1/2 of that to the machine shop. And that counts much of the duplicate and triplicate parts I ended up with, along the way.
Look on eBay. There's been a place in Texas ("MABBCO") I believe? Selling complete long blocks no core needed for $1700 ish and short blocks around $1200-ish completely remanufactured ready to go. No core needed. At $5g's, you'd be money ahead to start there at that price. Unless you are building something exotic.
