On the poulan 3700 I take the cylinder and sand it down by hand on a piece of sand paper on a very flat surface like a thick piece of glass or a flat piece of steel. I do a figure 8 when sanding and rotate it during this process to make sure it gets sanded down evenly on all sides.
Like Cut4fun said the top of the inside of the cylinder at the out side edges has a small squish band. That is where you need to make sure you have your clearance. I would not go any tighter than .020" on this saw because of expansion when it gets hot.