Your bus has the split system due to the lower GVW of the bus.
The front ends are the same no matter what the factory GVW was.
So yes, the parts from a higher GVW bus or truck of the same model would be a direct bolt in.
Parts from other buses can easily be modified to fit.
I'm currently installing a rad from a front engine bus in a rear engine bus.
Just be creative, and pull out the camera, angle grinder and the welder.
And don't forget the pics no matter what you do.