Going to try for a new tow vehicle

mcodecuda, maybe you misunderstood my statement. The Turbo is still pushing the motor a second or two at a full throttle. Try at a full throttle (even at a low speed). let off and brake, as in a panic stop. You will feel the push on what I'm referring too.
I sort of remember a braking issue on my early (‘94) truck where it might run out of vacuum if you applied the brakes a few times in succession.