Yes, we got 450gsm to run, but I wouldn't recommend doing it on a consistent basis. The OT-510 will not work with the PB-503. You would have to get the FS-532 instead. However, if you keep the PB in line, you're still going to get those roller marks. That has always been an issue for high color coverage. Try out that configurator I listed a few posts back...it will answer questions like these. It won't let you do any configuration that doesn't work...and it won't let you select "confirm" until you have at least the minimum components.