Ok so I have been to 3 places to see what size wipers this thing takes and all say 20 inch blades but a 20 inch blade on the passenger side is like 2 inches to long it doesnt even touch the windshield on the last 2 inches of the wiper and I was seeing if someone on here knew the right sizes because all 3 books say 20 for the blades

 

But the important thing is if the blade is long enough to get to the top and outer right-hand part of the windshield. Like setting a horizontally pivoting sprinkler, you cannot cover a square area perfectly without missing some spots or having overlap.

P.S. My 1999 Owners manual calls for 20" blades in the front and a 14" blade in the back.

 

What your seeing is common for GM vehicles like your Blazer. Mine's always been like that.