To Calculate the maximum speed of your Supercharger's Impeller or Rotors:

Supercharger Pulley Diameter: inches
Crank Pulley Diameter: inches
Supercharger gearbox ratio (3.6 for V-2 / V-3 Units): :1
Engine's rpm at Shift: rpm
Your Impeller or Rotor Speed: rpm
 

Maximum Impeller / Rotor Speeds
Vortech V-3 Sealed Unit (CAPA Oil System) - 50,000rpm
Vortech V-3 Oil Feed & Drain w/ Air Assist - 58,000rpm
Vortech V-7 JT Oil Feed & Drain w/ Air Assist - 60,000rpm
Vortech V-7 YSi Oil Feed & Drain w/ Air Assist - 65,000rpm
Powerdyne BD-11A - 38,000rpm
Eaton Supercharger - 18,000rpm

Ratios
Vortech w/ Helical Cut Gearbox (eg V-2, V-3) - 3.6:1
Vortech w/ Straight Cut Gearbox (eg V-1, V-7) - 3.45:1
Vortech V-20 and V-30 - 4.21:1
Paxton Novi 1000 / Novi 2000 - 3.5:1
Powerdyne BD-11A - 3.05:1
Eaton Supercharger (No Overdrive) - 1:1
Magnuson TVS Gilmer Rear Overdrive (3.5"/3.0") - 1.167:1
Magnuson TVS Gilmer Rear Underdrive (3.5"/3.0") - 0.857:1
CAPA Magnuson TVS Gilmer Rear Overdrive (36T/30T) - 1.2:1
CAPA Magnuson TVS Gilmer Rear Underdrive (30T/36T) - 0.833:1

Crank Pulleys
LSA Factory S/C Drive - 7.8"
VE-VF LS V8 Factory (P/N: 1117N) - 7.52"
VE-VF LS V8 Race (P/N: 1117SS) - 7.36"
VT-VZ LS V8 Factory (P/N: 1480ST) - 7.52"
VT-VZ LS V8 Race (P/N: 1480SS) - 7.36"
CAPA 8-Rib Crank Pulleys 205mm - 8.07"
CAPA VT 5.0L 180mm (Sold Pre-2020) - 7.09"
CAPA VT 5.0L 205mm (Sold 2020 On) - 8.07"
CAPA VN-VS 5.0L 205mm - 8.07"
CAPA Gilmer Crank Pulleys - 78T

Notes:
For LS-1 8-Rib Power Steer Drive Kits, enter the Crank Pulley Diameter, NOT the Power Steer Pulley Diameter.
For LS-1 Gilmer Power Steer Drive Kits, please use the Gilmer Power Steer Calculator (Link).