I wonder what you would find if you put quick connects & gauge at each head. You could swap gauges and test again for accuracy. You said they are telescopic? Could the left side be binding? Is there a section damaged or bent? Did you drop plumb lines at 45 & 90 (clock 3 & 6) with the car all the way up and measure from the lines to the cylinder at several points of each section? Did you check the rails? Where is the "T" in the line between the two pistons?
Maybe I grasping at straws?
