Just recently when I start my truck it's been making a loud noise kinda like a vacuum sound that won't go away, does anyone know why it's doing this and how it can be fixed?

 

All your vacuum lines are hooked up properly?

Also, the gasket around the filter box deteriorates. You can replace it with some weather seal available at Home Depot or any hardware store. Search the forum for "air filter gasket" and you should find more info on this.

 

+1 on the air filter box gasket, my engine was making a louder sound upon acceleration and I found that both the resonator from the airbox to the fenderwall had come loose and the gasket was completed worn out. About $3.00 later and 10 minutes, no more noise.