Nothing special about the bottom end of the test motor, just a high-mileage, LY6 with increased ring gap. The top end was another story and featured TFS 225 heads, a BTR Stage-3 turbo cam and Dorman LS6 intake. This 6.0L combo easily exceeded 500 horsepower in naturally-aspirated trim.
In preparation for the turbo testing, we installed a set of 6.0-liter truck manifolds. They were reversed to feed our custom Y-pipe. The use of the factory manifolds ensured plenty of plug and wire access.
The reverse truck manifolds fed this custom 2.5-inch Y-pipe built by JFab. Note the dual wastegate provisions and pressure tap to monitor the back pressure before the turbo.