I drilled and tapped into the block, about halfway down between the two center exhaust ports, into the water jacket. they were feed off of the side of the water pump, which pushed cool water into the center cylinders. also drilled and tapped holes into the back of the intake, for lines returning to the thermostat housing to complete the extra circuit, worked great . reamed out 1/4" pipe fittings w/ 3/8" lines will be cheap and effective. course that was on a sbc.
