Pretty likely that the OM617 pump, like the 603, can only put out 20-25% more power by turning the screw. I bet you could turn the 617 pump up and get 150hp with intercooling, though... past that, you'll probably need to ship it to Finland for some larger pump elements - same as the 603.

I'm not sure what kind of power the 617 can take in stock form. The 603 guys, like Mauri, are getting 400+hp with the stock pistons, heads, and everything else on the bottom end - just modifying the intake/exhaust manifolds, and the injection pump. And they run up to 2 bar (30psi) with the big Holset turbos, despite the 22:1 compression ratio. (Right, Mauri?) I'm not sure what advantage there would be to dropping the ratio.