It's really simple to do. You just need to block off the upper pipe nipple (on the head pipe), then remove the brass fitting on the top side of the chamber and run a m5x.8 tap through the inner section. Put a plug in the inner section with locktite.
Then put a cap back in place of the fitting you.remove to access the plug.
Next, drill.and tap the end of the chamber (next to the exhaust hose) for a spray bay to keep the exhaust.cool and feed the spray bar from a water source somewhere. I used the oem 1/4" branch off of the existing exhaust manifold fitting to feed the spray bay.with cool water directly.from the pump.