Cylinders

I have used two inch to 2.5 inch brass & cast iron cylinders. Considering initial cost I believed brass ( 2 inch) was a better deal. Recently, I have installed 2.5 inch brass and have been pleased with their performance. For approximately 30 dollars more one can get the 2.5 inch rather than the 2 inch. The 2.5 pumps quite a bit more water per stroke. After reworking a number of cylinders, I have concluded that if you have any doubt about the condition of a cylinder, better just get a new one.