Engine seize
 

Hey guys hope someone might have some thoughts here on where to investigate or maybe even had this happen to them and solved the issue, it's long but want to make sure I include everything. Truck is an 86 4wd with a 22re bone stock in great shape cosmetically, but was running rough. A buddy and I pulled the engine and did a rebuild on it, metal guides, new chain, new head, new mains new rods all plastigauged and torqued, pistons and rings all in spec. Put it all back together, set the timing and was running fantastic. Bed is off for a full body prime and paint so we pulled it out of the garage to wash the frame. Pulled out fine but on going back into the garage paused for a second with the motor running to move a sleeping dog. Truck died while paused no knocks squeaks or hisses, oil pressure is fine coolant temp is fine, go to restart and starter feels like it isnt getting enough battery, check battery all good, double check neural, all good, try to turn crank by hand with a breaker bar, no go, hard locked, heart sinks. Pull out plugs and try to turn it again with a breaker bar, no luck. Tap the starter again, no luck. Tap it 3 more time and get a little movement, then a full revolution, then a free spinning crank. Put plugs back in, fires right up runs perfectly smooth no knocks no bumps nothing. My only thought is a seized main or rod seized cam or valve or loose wrench in the timing gears or something, thoughts?

You have to tight of a clearance on the rods or crank bearings. Heats up bearings get tight, cools off loosen off. Did you take the block and crank to a machine shop?