Small Engines (Lawn Mowers, etc.): riding mower blade installation, blades of grass, bagger

Question
Morning.
I have a Craftsman 42 inch two blade riding mower.
How important is it to have the two blades even or perfectly paralel with one another?
Since I put in new blades I don't seem to have the same force of air pushing the cut blades of grass  up the chute into the hopper.

thanks

Answer
 Hello Mark:

 Are you sure the Blades are mounted Correctly? It doesnt matter how the Blades are put on as long as they have the Lift Ear away from the Grass. Also, does the New Blades have the Same Lift Ear as the Old Blades? They have Bagger Blades and High Lift Blades and Regular Lift Blades. Hope this Helps.

 Good Luck

 Respectfully

 John