Need a 5.3L engine that will fit a '99 Z71 - Two words build it I have a spare in the floor of my shop with the plans of building ...

Two words "build it" I have a spare in the floor of my shop with the plans of building it.

Yeah, I would love to re-build it...but I don't have anything to put it into. My 6.0L is running strong. My nephew has a Blazer and would love to have it dropped in there but the cost is gonna be steep. What would be a rough estimate of basically rebuilding it entirely?

That gonna depend on what all is still usable in it. If the crank and rods are hurt it could get expensive quickly. If all the internals are usable and you get any machining done thats needes and a rebuild kit I would estimate between about $800-1500 just all depending how much machining there is and if they have to bore the cylinders or not. I actually had a parts house tell me they didnt carry rebuild kits for the LS engine because its cheaper to get a new one, but I priced a 5.3 long block from jegs at about $3000

We haven't opened it up that far to see what exactly is damaged. The oil pan is off and there is no obvious damage to rods and crank but then again I wouldn't expect to see any without pulling it apart. One good sign is that the crank will still turn and nothing seems seized/locked. But the evidence in the oil pan was clearly ground up metal and lots of thick sludge. The sludge had clogged the oil pick-up tube and we assume that's what did the damage.

You could be lucky enough that the metal pieces are only bearing material and it not have worn completely thru the bearing and start wearing into the block, rods, or cam but wont be able to tell till you pull it apart further.

Just wanted to update everyone on that motor change we did over a month ago. We did find someone who wanted to take and rebuild the motor....and I'm waiting to hear details. The transplant motor is still running strong!!!

So, did you sell the old one, or is someone just going to build it for you?

Nah, the person who got it will rebuild it for himself.