Trouble printing perpendicular walls
You may be getting shrinking due to cooling on the non-top and non-bottom layers. Sixty percent infill is rather substantial. I'm printing 20 hour pieces in ABS at 100 °C / 250 °C using ten percent infill and getting nothing like what your image shows.
Can you do with a lower infill? More isn't always stronger. Four perimeter shells may be a factor but you'll probably see a difference with a smaller percentage infill.