Should alternator be putting out 13-14 volts?

Well I had the mechanic recheck the voltage after I swapped alternators out again. I also removed the voltage regulator and sanded down to bare metal the mounting bolt areas. I made sure the battery was charged and the cables tightened. It still only put out about 11.80 volts and when the idle was increased to 1200-1500 it only went a little closer to 12 volts. It's got all new wiring harnesses and a new NOS ammeter. Should the voltmeter read 13+ volts when I have the leads touching the + and - while the engine is running? So what's next to check? I have the engine ground that's bolted under one of the blower motor nuts and goes to a bolt through the bellhousing and that's it. I ordered another OEM voltage regulator since I had to order something else for the car. The mechanic says he's having a similar problem with a 68 Chrysler 300 and was able to get that one to charge 13-14 volts by jump wiring something, I don't remember how he said he got it to do it. But what do I need to check next in order to see if my regulator is bad or something else?