318 LA rebuild after losing a valve seat

Righty Tighty said
The crank rotated smooth as silk by hand before the pistons. After the first and second I noticed a marked increase in resistance.

The reman didn't come with bearings, I ordered them separately.

It sounds like the bearings are your issue... Check to make sure both ends of the bearing shells sit flush when you install them in the rod and cap... If they stick up too high, that can cause problems...