Review the PDF linked below for calculations for the lifting arm. If the PTO is driven on the low gear side (14 to 64), then an additional reduction of approximately 8:1 will be required to drive the arm. This is easily achievable in two stages. If the PTO is driven from the high gear side (30 to 48), then an additional reduction of about 23:1 is required – still achievable in two stages, but requires rather large and small sprockets. With 4 CIMS, the lift can occur in about 1/2 second. With only 2 CIMS, it could still work if geared properly (twice the reduction), but it would take twice as long.
The calculations below are presented in a fashion that should be understandable by the astute high-school student who has completed a Physics class.