Paul -How ya gonna get it up your driveway? (Sorry, couldn't resist!)
There is a control valve mounted to the gearbox that controls fluid pressure flow to the hyd. cylinder , HTH, Glen
Paul, the OE power steering with the ram assist is OK, but not nearly as tight and precise as an integral power steering. This is why a lot of buses of that vintage were converted. The MC5A,B or C is very similar to the 8 or 9, so your info on Bus 101 would be relevant.JC
Was the -9 gear a direct bolt in?