Nissan Repair: new pistons, nissan 240sx, proper clearance

Question
I am trying to rebuild a 1992 nissan 240sx .every thing was going smoothly until I tried to turn the engine with the new pistons in and the engine assembled. I had to use a breaker bar with a cheater pipe to turn it. I checked all the clearances and they were within specs. I removed the pistons again 1 at a time and narrowed it down to #3 & 4 that seem to make it hard to turn. the bottom skirt of #4 piston showed signs of rubbing against the cylinder wall at center and bottom. #3 piston is very hard to slid into the cylinder. I've worked on several cars and never had this much trouble getting them to turn after installing new pistons. Any help would be appreciated

Answer
Glenn,

If cylinders 3 and 4 are tight I would check the clearances to make sure the pistons are not too tight and that those cylinders need to be honed to a larger size.  Also,make sure the rods are not bent causing the pistons to drag at mid travel.  If the pistons are cleared to the proper clearance and you have binding the rods could be bent.  Lastly, check the rings for proper gap clearance to make sure they are not binding in the bore.  The pistons and rings should be checked at the tip, middle and bottom of the bore to make sure you have good clearance.  Read the manufacturers specifications on the pistons and rings.  Also, if the machine shop has a specification sheet for the machine work that would help too.