I installed my fuel flow sensor in the flex line between the fuel pump and the servo (fuel control unit/throttle body).  There is a flex line before, straight fittings before and after. followed by another flex line.  I used an aluminum heat shield/mounting bracket that was clamped to the intake tubes.  Seems to work just fine and I haven't seen the need to change the coefficient that was originally in the GRI unit.  I don't use a current sensor as I feel that monitoring system voltage is adequate.  I mounted their oil pressure sender (the VDO variable resistance device) directly to the oil pressure tap at the back of the engine with a stainless steel 45-degree fitting (street el).