NOTE: tested product.
New solid state technology for smooth gauge & performance and no adjustment needed.
"Original voltage regulators had a tendency to make the gauge needle jumpy"
IMPORTANT!

Disconnect battery before replacing and make sure this voltage regulator is properly grounded before reconnecting the battery.
If not grounded properly it will cause the regullator to have improper output, give animproper gauge reading and get very hot, possibly damaging the regulator.

Also fits other FORD, earlier than 1966.