Does anyone know the ins and outs of matching power steering pumps to steering gearboxes?

This winter (and likely spring and summer) I'll be installing a VW TDI engine in a 1984 W123 wagon. I'd like to retain the nice load-leveling rear suspension, but of course the VW engine does not have the head-mounted hydraulic pump of the OM617.

I'm therefore looking at the tandem pumps used on the later cars. Obviously a good deal of fabrication will be required to get one of these pumps to package and work with the VW accessory drive, but the real worry for me is that the hydraulics match up.

I took a look at www.mbpumps.com and see that the pressures for the W124 pumps are considerably higher than that of the W123. Do you think the combination of W124 pump and W123 steering box will work?

Any advice is much appreciated!

Ted

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1983 240D automatic, Orient Red, 174K
1983 240D manual, Biscayne Blue, sold at 341K