KettleHouse

1984 Toyota 22r long bed - Recently I started hearing a clicking type noise coming from underneath my truck, sounds like it is coming from right below my seat or a little bit back. It sounds like someone running their fingernail over a metal comb. It only seems to be happening when giving it gas in 1 and 2nd (although I did hear it in 3rd and 4th when I had a heavy load in it). If I slightly change the pressure on the gas pedal more or less it will stop. I have tried revving my engine in neutral and the sound is not there. It is only there when I am moving / in gear. Anyone thoughts on what this might be? Thanks