Have a friend who purchased a 1961 AC gas (not sure of model). It had one cylinder stuck when he got it. He removed the sleeves and pistons and ordered a new set. When replacing them cylinder # 1 was fine but as he got # 2 in was very hard to move and when 3 and 4 were put in it was so tight you could not move them at all. He jacked tractor up and put in gear but could not move them at all. What are some things he should be looking at. He said he numbered them as he removed them to get the (rods I think) matched to the cylinder they were originally in. Not in backwards he said as they will fit only one way and the arrow on top of pistons pointing in correct direction. Wish I could be more exact but not versed in this at all. Will relay any ideas anyone may have and thank you in advance for your time.