Slant 6 Turbo 68Dart Project

i havent blown a hose yet. thats pretty crazy. i have a mix of regular vacuum hose and fuel injection hose for my various references. ill make it all fi hose sooner or later. 5psi is a good starting point. pretty hard to hurt the motor with that little bit of boost. hell i ran my normal timing at 5psi and it flew and didnt blow up. on regular gas no less.

found this in the support section of the page you listed.

2.4 Sensor Calibration
Once the unit has been wired and a suitable location has been found for both
the gauge and the sensor it is time to do the sensor calibration. Innovate
Motorsports’ ‘Direct Digital’ wideband measurement principal allows you to
calibrate the sensor to compensate for sensor wear. This procedure takes
just a few moments and it will ensure the most accurate readings throughout
the oxygen sensor’s life. This procedure is required anytime a NEW oxygen
sensor is installed.
The calibration procedure requires that the oxygen sensor be in free air, this
means removed from the exhaust system completely.
1. With the sensor disconnected, apply power to the MTX-L.
When power is applied, all three digits will light up and the needle bar will
sweep once through all LEDs. Then the status light will turn red and the
numeric display will read “E2”. This is an error code, indicating that no
sensor is detected. Leave unit powered on for minimum 30 seconds.
2. Power down the MTX-L and attach the oxygen sensor using the
cable provided. When making these connections, make sure they
are fully seated and locked. Again, make sure that the sensor is in
free air (not in the exhaust).
3. Power up the MTX-L.
Again, the display should ‘sweep’, but instead of an error, the display will
display “Htr”. This indicates that the sensor is being heated up to
operating temperature. After 30-60 seconds, the display will switch from
“Htr” to “CAL”, indicating that the sensor is being calibrated. A few
seconds later, your MTX-L will begin displaying AFR. Since the sensor is
in free air, the gauge will default to the upper limit of 22.4.
The calibration procedure has completed and the system is now ready
for use.
Important: You can disconnect and reconnect the sensor and sensor
cable for installation without losing your calibration. However, if you
power up the MTX-L without a sensor connected, your calibration will
be reset (see step #1 above).

might be worth a try if you havent yet.