Shims Under Main and Rod bearings

It's better to simply not convert to milimeters when dealing with US inch-sized parts.

BigBlock Mopar engines usually had a Maltese cross mark, or something like that, on the engine casting if something was different with the bearings.
Not sure if they did this also on Small Blocks?

Why did you buy a truck rebuildkit?
The pistons are probably super low compression and basicly ashtrays.
Do some math the 1.741 Compression Height to see where you end up on the static compression.