Anet A8 Y-Carriage upgrade

Like http://www.thingiverse.com/thing:2063292 this is an upgrade to the Anet y-carriage with clearance for the y-axis motor and more stiffness than the original part delivered.
Outer dimensions are 219x219mm so should fit every printer with a similar design like Anet A6 etc.
I removed the option to mount only three bearings since the original P3Steel evolved in removing this option, so why would one add it again?
Since the distance of the holes on the P3Steel and the Anet for mounting the bea