With the form below, you can calculate the ratio of your connecting rod to the crankshaft stroke. Longer rods, which result in a higher ratio, favor the mid and upper RPM area. Shorter rods, or a lower ratio, improve low-end torque. The ratio should fall in the range of 1.65 to 2.00.
Some typical information is listed below for reference.
Stroker motors should have longer rods if you can afford them.