Bearing information

Here is what I found doing research to replace my impeller chaft bearings.

Part number is ME-1103. Made in the US. There are 3 types of pre-load available: Light 9lbs, Medium 27 lbs and Heavy 54 lbs. I am not sure which one I need. If anybody has any idea please let me know. They are sold in pair as there are two on the shaft opposing each other.

Anybody has any idea how much torque to use when tightening the impeller nut?

SPECS:
Bore: 17mm
Outside Diameter: 35mm
Width: 10mm
Load Ratings - Static: 1079lbs - Dynamic: 1709lbs
Speed Ratings - Oil: 69,000rom - Grease: 44,850rpm
Preload Levels: Mentioned above.