Problem solved! This is an older model with a combined tilt/lift lever on the steering column. That means there is a lot of linkage and a bellcrank. One bracket had move creating excessive slop in the lift portion of the mecanism. My previous efforts were not fully moving the spool. I guess the increased line pressure cause the spool to fully engage. I adjusted the linkage and it works great. This remote mounting of the valve with extensive linkage was abandoned several years ago for good reason.