Weird noise from transmission

[Lakehimself]

My 91 Pickup has been a real warrior, however lately there has been a weird noise from the transmission. I think it may be the clutch going bad however I am not sure. I took it to a transmission shop and had the oil changed and they noise was still there and they had no clue what it was. It sounds like a light scraping, only when I get above 1200 RPM's. I don't notice anything different in the drive of the truck just the weird noise. I changed the clutch on it about 20k miles ago but maybe it could be going bad early?

[Towncivilian]

Assuming you have a 4WD truck with the FS5R30A transmission, you need to overfill your transmission. See this thread on NPORA.

What type of fluid did the shop use? If it's anything but GL-4 (GL-4 and GL-5 rated fluid won't work), drain that crap and fill it with GL-4 only fluid. Redline MT-90 and Amsoil MTG are great fluids.