cab heater in 190

I need some advice  on where to tap into the  engine at for a hot water supply  and return for a heater in the cab and an engine tank heater on my one-ninety gas (not an XT). One possibility, is that on the right side of the engine where one soft plug is at, the block is machined flat and has 1 bolt hole on each  side of the plug, as if you could pop the soft plug out and bolt on some sort of adapter that may be available some where? Any thoughts on that?  Then, the 2nd connection could possibly take place right below the thermostat, where there is a flat round area cast into the housing, that could be drilled out and have threads tapped into it for a fitting. Anyone ever been there and done that before? Any thoughts or advice, or plumbing diagrams would be welcomed. Thanks in advance.   Darrel

On my 7000, the thermostat housing has ports for the cab heater.  I'm not really familiar with the head or thermostat housing on a 190xt, but this may be possible.  The return line goes into the water pump's suction line.  

Hot water is taken from the thermostat hsg under the thermostat....there might be a plug that could be removed already or drill/tap for 3/8 "pipe. Return water goes into the water pump outlet which the lower radiator hose is now attached to. Maybe have to again drill a hole on the top of it and thread to 3/8" pipe OR there could already be a removeable plug. Both pieces can be removed from the engine for drilling/tapping.