It should spin quite smoothly using one hand with the caps tightened down, so you're right there's probably something wrong.
Yes crank is STD and bearings are STD - but did you check it with plastigage anyway? Mistakes have been made before, even if you trust the machinist and the parts this is a sure fire way to find any problems. Cheap insurance, just takes a little extra time.
Second thought: on my Willys Jeep I found the new rear main seal was defective, being about 1/8" too long when compared to the old one. Tightening down the rear cap sinched down the crank and it wouldn't return. Bought a replacement seal and it fit correctly.
-Boyo
