New bearings, difficult to rotate the crankshaft.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
"Checking the ring end gap is also a must"
Do you have a "feel" for how tight the pistons/ rings are in the bores? Are these used pistons? ANY CHANCE there is dirt/ carbon down in piston ring grooves?
NOW IS THE TIME. I'd pull the short block apart and start over.
Don't necessarily need to remove the crank. BUT Pull the main caps and plastigauge the crank, then MEASURE the turning torque of the crank. At this point you should EASILY be able to rotate the crank by hand by pulling on the crank throws.
Pull at least one top ring, and use the piston to "square" the ring in the bore, and measure the gap.
If there is ANY possibility that the ring grooves were not scraped clean, remove the rings and do so.
Then put ONE / piston in at a time, check with plastigauge, and then check the turning torque of the crank.
But above and beyond all this, WHAT IS the turning torque of the assembly? Saying that it's "too hard" or someone else saying "should be able to turn by hand" is pretty subjective. "Turn by hand" with WHAT? hanging onto a 1 foot bar? a 2 foot bar? a 6 ft bar?
MOST OF the turning torque in a new short block could very well be the rings.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
"Checking the ring end gap is also a must"
Do you have a "feel" for how tight the pistons/ rings are in the bores? Are these used pistons? ANY CHANCE there is dirt/ carbon down in piston ring grooves?
NOW IS THE TIME. I'd pull the short block apart and start over.
Don't necessarily need to remove the crank. BUT Pull the main caps and plastigauge the crank, then MEASURE the turning torque of the crank. At this point you should EASILY be able to rotate the crank by hand by pulling on the crank throws.
Pull at least one top ring, and use the piston to "square" the ring in the bore, and measure the gap.
If there is ANY possibility that the ring grooves were not scraped clean, remove the rings and do so.
Then put ONE / piston in at a time, check with plastigauge, and then check the turning torque of the crank.
But above and beyond all this, WHAT IS the turning torque of the assembly? Saying that it's "too hard" or someone else saying "should be able to turn by hand" is pretty subjective. "Turn by hand" with WHAT? hanging onto a 1 foot bar? a 2 foot bar? a 6 ft bar?
MOST OF the turning torque in a new short block could very well be the rings.