I recently swapped my 96 f150 from a 5 to a 4 speed and now the dang thing started making a noise. I thinking it is the throw out bearing but I don't really know how to tell.

It does stop and change pitch as I press the clutch.

 

Did you install a new clutch and bearing when you did the swap? did you grease the input shaft that the bearing rides on?
I have seen faulty bearings right out of the package.
Best way I found to tell for sure is to put the truck in the air on all 4 corners with jack stands and have someone climb under it while it's running and engage the clutch back and forth.

 

New clutch and bearings while I had it out from under the truck. It's been a little while now but I'm pretty darn sure we greased it. And it seems to come and go as it pleases like this morning it didn't make a noise until I was sitting with it idling.

 

it was a bad throwout bearing it seemed to have got stuck burned up the clutch and where a good grove in the pilot shaft sleeve

 

Well that sucks, but at least you found the problem before real major damage was done. Good luck with the new one.