First 3D printer, bed out of level  

First 3D printer, bed out of level

I'm completely new to 3D printing and bought and built the kit myself. I think I finally have the PINDA probe in a sweet spot, and the calibrations all run through and say they are alright, that firmware will adjust. I run the bed leveling calibration and then print the v2 calibration gcode while using live Z adjust to get it close to where the PLA with stick. My prints are OK, but taller ones, even a few inches are skewed toward the rear of the printer. Placing a piece of paper on the bed and starting from "home" the nozzle is slightly above the paper. As I bring the bed forward (Y axis), the nozzle gets closer and closer until around 160 it grabs the paper and starts to drag it along the bed.
Is the main frame out square? I have everything pretty tight and have measured 100mm from the back side nuts to the Y-axis corner on both threaded rods.
I've tried manually changing the bed level "Rear" to 50 and the "Front" to -25 just to see if it made a difference, and it didn't seem to. Any tips anyone can share? Something I can check?