Technical 700r4 solenoid with one wire

I put a 700r4 in my 57 chevy and am replacing the solenoid. Mine is one wire and all I’ve found are two wires. Anyone familiar with where to find a one wire solenoid or another alternative? Thanks

 

Wouldn't the extra terminal just be a ground lead? Yours likely grounded through the trans. Add some thread sealant and no more ground. The new design (if I am correct in this ***umption) would be the better route, just ground the extra terminal

 

The 1 wire solenoid was the early type and I believe they are not available anymore. Put a ring terminal on the black wire and ground it to to one of the solenoid bolts. Been doing this for years.

 

Thanks for the help guys I’ll get on it tomorrow. This is a great site for help