50 flathead V8 temp. sending units

[johndob1929]

can anyone tell me if the stock sending units (one in each head) on my 50 flathead V8 (one has 2 wires on it and one has one wire but the wires were cut right at the sending units) are for a dummy light or will they run a old electric temp. gage ? i want to run the old electric temp. gage. do i need special sending units (if so, what am am i looking for ?). how do i wire them ? i am still using the original 6 volt, positive ground system. thanks - john