2004 5.7 hemi Alternator

[MEH]

I have installed a 2004 5.7 Hemi in my 74 cuda. The alternator at idle is putting out 27-30 volts. I have not run the wire from the post to the battery yet due to the voltage. If anyone else has had this issue or know the cause or fix please let me know. This is the last final issue before my road tests.  Thanks

[Jousi]

You must put the supply cable directly to the battery plus, otherwise the diods will burn pretty fast.

Also I would do the powering routing with relay and direct battery voltage so charging will be stable all the time...
I did like this:
Ignition switch is controlling relay, which supply direct voltage from battery to the voltage regulator and alternator, field ground normally to the regulator.  I used earlier voltage regulator with OEM wiring without relay and it was jumping close to 15 time to time.

Of course if you are using OEM Hemi ECU which controls the charging, then forget everything I wrote, exempt first sentence  .