Ford Repair: 94 Ford Ranger, ford ranger, western auto

Question
I have a 94 Ford Ranger,6cyl,4.0ltr,2wd,ext cab, w/157,000 miles. The alternator gauge on the dash has always read a little to the +plus side. Recently, it dropped to the
-minus side and a battery light on the dash came on. My mechanic put a meter on the battery and it showed 12.4 volts.On his advice, I replaced the alternator and the battery(alt was 2+ yrs and battery was 4+ yrs). Now the dash gauge reads way to the +plus side but still within the "normal" bracket. When we put the meter back on it, it reads 14.8 volts which my mech says is a little high. My question is: Is this within an acceptable spec for this system or do I have to change the alternator again? Will the increased voltage "cook" the new battery I just put in? Any information you may have will be helpful. Thanks for your time.

Answer
Yes this is within specifications.Was the tool you're mechanic used hand held or was it on a cart.You need the charging system load tested.Advance Auto,Western Auto,and AutoZone all do this free of charge.With all new parts I think that you have fixed the problem.That away to stay on top of it.