Hydroboost/ps pump issues?

Do you have U/D pulleys at all?

As you press the pedal the load on the PS pump does increase. As you’ll note, applying unrealistic pressure to the pedal will increase load to the point the engine may stall.

I have hydroboost on my fox and note the same thing but it’s not an apples to apples comparison since mine is a retrofit and I do not have the same pump. I can load up the engine pretty well, but like you said, to do this requires leg pressure that I’ll never use during actual driving. My car stops well with very little pressure which does not load up the engine like it does of I stand on the pedal

I had an 03GT but it’s been years since I had it so I don’t remember how a new, stock new edge behaved.

Do you hear a hissing/buzzing noise from the relief valve prior to the pump load stalling out the engine?