Combines JD 630F Hydraflex

how much presure are you runningIJ what combine do you have the header onIJ

It depends on what I am doing, some times I run 1000psi and up to 1800psi but changing pressure will not change the height relation between the cutter bar and platform.

600 heads will not change cutterbar height like the 900 heads would. The 600 cutterbar cuts at about 2-2.5 in and cannot be altered with hydraflex pressure.

that is true on the 50 and up machines, but on a 9600 you still have the dial a matic box on a 600 header that could be adjusted.