I changed the crank on a 78 2.3 to an 89 2.3 crank, replaced all the bearings and the crank won't turn with the mains tight, loosen the mains and it turns. Factory crank with standard bearings. What am I doing wrong?

 

Wrong bearings?

 

assuming you have the correct bearings (use plastiguage to verify)

Loosen the the mains, apply lube to the bearings & crank, with the bearings only snug, turn the crank by hand (with a wrench), tighten a little more, turn again......yes your arm will get tired but this is how it is done, assuming you have the correct bearing and bolt torque settings......

 

Got it fixed, rod had a shoulder and would get hung up, ground it off and it spins