Chipper blade weights/balancing...how much is too much?

[Forestviller]

Any rule of thumb or estimate on what's an acceptable difference in blade weights for a chipper? Model is an Echo Bearcat 4420 chipper, each blade weighs 1100 grams (about 2.5 pounds) and the rotor is 49 pounds.
After multiple sharpenings the blades differ by about 10 grams (two blades). Not wanting to strain the main bearing but also trying to avoid unnecessary sharpening to shed weight from the one blade.
Any thoughts on what'd be a safe difference in blade weights? 10 grams is 1% which sounds ok but at a few thousand RPM a couple % difference could be bad...

 

[Forestviller]

Pic of the Echo 4420. Great, very well designed machine for anyone curious. I've probably put 50 hours on it now.

 

[Del_]

You need to keep the blades the same length so they take the same size chip.

Cutting different size chips also throws the loading out of balance.