I have used a 3120 alot , and alot of different ones. I use 3/8 chain on them and if the bar is 24 inches long I use a bigger gear, 9 or 10 tooth , it depended on what I was using the saw for. If you use the horsepower it doesnot matter if it log is big or small, the 3120 or 088 will cut it faster than a smaller saw