Did you notice oil pressure drop to 0 before the engine died?
Yes, as above mentioned the Cam Synchronizer on the 3.0l is a common issue but usually will have a high pitched squealing noise(similar to slipping fan belt sound) weeks before it fails.
Cam Synchronizer is in the old distributor hole, and like the old distributor did, it powers the oil pump, so when the Cam Synchronizer fails oil pump stops working.
Could even be a bad oil filter or oil pump failure that caused oil pressure to drop.
Oil cools the bearings and if oil flows stops the bearings over heat within a few seconds, this causes them to soften and "weld" themselves to the crank, engine RPMs start dropping and then stop, since the bearings are now softened and "welded" to the crank it will no longer turn, with starter or manually.
You should have heard a "ticking" noise from the lifters/rockers in the seconds before motor died, lack of oil pressure would cause that.
If no oil light or 0 pressure on gauge, and no "ticking" was heard then you could have a spun main bearing, just from failure of that one bearing or clogged oil passage on that bearing.
I assume truck will roll in neutral, so transmission isn't the issue?
Manual or automatic?
I also assume you have removed all the spark plugs and looked at each, and none show signs of damage, and engine/crank still won't turn with no spark plugs in place.
There is really no way to test for melted or spun bearings, engine must be removed and oil pan removed, then remove each bearing cap, main and rod caps, and see which one failed.
Last edited by RonD; 03-18-2015 at 10:14 AM.