Correct Alternator for '68 Dart GTS
Alt braket
Basic kit for a cast iron pre 70ish water pump small block.
Your 68 would have had a grounded field electro mechanical voltage regulator and would look like this
And be mounted to the drivers side of the master cyl on the firewall.
It has one wire that comes from the ignition and then I receive that runs to the Alternator Field terminal.
Your alternator would have been a grounded field (round back) type. Round back core are few and far between so rebuilders take an isolated field (Square back) type and ground one of the field terminals internally and it becomes a functionally equivalent substitute.
Lastly there are single pulley and double pulley alternators that will be dependent on your alt, water pump, ps pump, AC setup.
Look in your factory service manual for additional belt routing etc.
Post a photo of the alt you bought.
There are too many unknowns about what you have now to know what you need.
Alt braket
Basic kit for a cast iron pre 70ish water pump small block.
Your 68 would have had a grounded field electro mechanical voltage regulator and would look like this
And be mounted to the drivers side of the master cyl on the firewall.
It has one wire that comes from the ignition and then I receive that runs to the Alternator Field terminal.
Your alternator would have been a grounded field (round back) type. Round back core are few and far between so rebuilders take an isolated field (Square back) type and ground one of the field terminals internally and it becomes a functionally equivalent substitute.
Lastly there are single pulley and double pulley alternators that will be dependent on your alt, water pump, ps pump, AC setup.
Look in your factory service manual for additional belt routing etc.
Post a photo of the alt you bought.
There are too many unknowns about what you have now to know what you need.