water temp gauge

currently rebuilding a 56 chev with bad wiring. Need to check water temp. Is there a gauge that can be inserted in back of 350 chev block where sending unit is to read temp while working on engine?

There should be a place on the side of the block where u can put a temp gauge and wire red to hot & black to ground, i have three water temp gauges in my car one for each head and one for the radiator.

thanks for your help....I'll give this a try....highjumper