Project Helen,

The temp gauge is indeed a sealed system and cannot be broken into or extended. The hollow tube is filled with ether and must remain attached to the gauge and leak free to work.

I would think your options would be to find access to the water jacket in an area that the stock system can reach, see if after market suppliers make a 'faux' stock electric gauge or a gauge with an extended tube.

There must be a good answer to this because there are a million SBC transplants into these AD rigs all the time.

Stuart