Squareback vs round back alternator?
What do you have now?
Do you want to keep the oem look?
I agree alternators are cheap, but round back alternators are few and far between ( I'm going through this right now)
Alternators 101...
Mopar had 4 alternators
Round back single field wire
Round back dual field wire
Square back
wired as a single field wire (note green wire to one field wire)
This is also a square back wired as a one field wire (one of the terminals is internally grounded, note the tab is clipped off, this is what you will get from the parts store if you buy a "round back" alternator 99% of the time)
Square back dual field wire.
If you have the old style square voltage regulator
you need a single field wire alt regardless of round or square
If you have the newer rectangular VR with triangular shaped connector
you need the dual field wire alternator regardless of round or square
The square backs have a higher output than round BUT if you have oem electronics on your car there is no need for a higher output alt. Infact it can de detrimental.
Alternators are relitivily easy to rebuild and parts are readily available.
A press is the most complicated part of the process.
The diameter of the pulley is a main contributer of poor charging at idle.
I recently posted "diameter, diameter, diameter, alternator pulley" showing the ammeter bouncing with a 2.75 dia pulley vs a 2.5 dia pulley
Diameter, diameter, diameter, alternator pulleys