D6h slow weak.

I have a d6h that travels very slow and high revs are needed. I suspect it is a torque converter pressure problem as the propshaft does not turn much and is very slow spinning. The converter inlet pressure at idle is 130psi. Converter outlet is 0 at idle. Main pressure at filter is 400psi. Can anyone tell me where and how to check the converter ratio valve? Checked and cleaned the converter relief valve.

Thank you

D6h slow weak.