99 motor in 93, any one drilled the head for the temp sensor ?

I am trying to get a 99 TJ motor into a 93 XJ and the rear temp sensor location in the head is not there on the newer motors. Has any one drilled out the head on one of the newer ones to put in the temp sensor ? Is this too risky ? or should I put the sensor in the heater line ?
Thanks,
Dave

Although it should be a simple job to drill and tap the head, I would be hesitant to do it. The temp sensor you refer to is only for the gauge on the instrument panel and doesn't provide any input to the ECU (PCM), so it could be located anywhere it will be exposed to coolant flow.