I have the 2" version of this gauge, Westach P/N 2DC2-30SS, steering column mounted in their gauge pod.
My turbo is a stock Garrett VNT-15 from a MkIV Jetta 1.9L TDI, with mechanical vane control - - so I'm using a Westach 1/8" EGT thermocouple that has a 4" probe inserted on the EGR cooler flange on the exhaust manifold into the turbo exit gas flow path and is wired up with a Westach wiring harness.
The boost pressure is transmitted via the included ~1/8" rubber tubing from Westach; the boost source is connected to the 90 degree aluminum elbow at the top of the stock VW 1.6L turbo intake manifold. Works great to have boost and EGT data in one gauge.