I've been trying to hook up an aftermarket temperature gauge. The problem I'm having is finding a gauge with a sending unit that fits the small opening in the slant six head. I'd rather not add a sensor in a radiator or heater hose, but I don't want to drill and tap a larger opening in the head, either. Are these my only choices?

VM

When I've had that problem with a mechanical temp gauge, I found brass adaptors that did the trick, but made sure the sensor stuck down far enough to touch the coolant.

If it's electric, you can probably find a smaller sensor of the right range. Most electric sensors simply change resistance with temperature, and often vendors use the GM range (but not always). A multimeter and a pot of water boiling on the stove would let you determine what kind of sensor you have.

Thought autometer had a generic unit for 1/8" NPT sensors?

One trick that works well is to drill and tap the thermostat housing to accept your new sender, and just leave the stock sender in the head. This way you have all the room you need to work with (to drill and tap to the required size) and you get to "see" the thermostat open on your new aftermarket gauge.

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