Here is some tech videos including gear whine issues on a 8.8..
Also check out episode 8...lol
http://www.flatratetech.com/index.php?categoryid=4
Intresting read.
However, stock / factory ring sets will not have a whine or shouldnt. Recalls, recalls and more recalls would be seen if factory vehicles had this noise. Thats why factory warrantys are VOID if aftermarket gears are installed and for other reasons of course.
The Whine vs no whine has been a debate like Ford Vs chevy. Its been beaten to death over and over and everyone will have their own opinion as to whats right and whats wrong.
If gears whine, it doesnt mean they are installed incorrect. Some materials have harmonics to them. Theres a big difference between the whine you hear with a incorrect install, a bearing whine, or the whine of a "noisy" set of gears. They are all distinct. It takes a trained ear to distinguish. You can have a accel whine, a decel whine, or just a plain old whine.
Gears marked other than Ford
may be noisey.
I will agree 100% that if any part of the assembly is not installed correct you will experience whine or worse also.Thats a given on any assembly.
LOU:
What part number do you have for the gears? Who makes them? Again look at my above post about the part numbers ending in M-A if they are FRPP. This will forsure help determine whats going on. Ending in M means MOTIVE and if you look at Motives website they have detailed install tech instructions that differ slightly from Fords. DOnt ask me why but they do. THis may also be a issues to look at because of the difference. It may well be a install issue from Motive vs Ford vs the tech installer or other.
Its just all guessing till you have Straightline go through it again. My bet is that you are hearing what many others do from a properly installed aftermarket gear getting some harmonic feedback. Like Jeff said above his whine did noticably went away after time. If you have a incorrectly installed assembly over time it will get worse not better.
Another thing is that you cant just jump in and rip through the gears untill they break in and mesh right. What you should have been told is... Heat cycles - drive easy for 10-15 minutes to heat them up, then park it for a few hours to allow it to cool. Do this 3-5 times and then take it easy driving for the first week to be absolutely safe. If not broken in corretcly you will damage the new install thus causing any of the above mentioned issues.
Edit:
Another thing to consider is that many guys who may not expeirence this slight whine may not be able to hear it do to the aftermarket exhust drone in the car. I know my car is not quiet and I couldnt detect a whine in my gears for the life of me unless I was running Richmonds or Motives
And just by me saying that does not mean by any means they are bad gears! Just a bit noisier over others is all.
A vibration is more to worrie about then a whine imo.
Please update when you get back from the shop so we all know whats up eh.