livelovesole

This happens every once pretty often but not every time. Whenever I'm at a dead stop and go from neutral to 1st gear, as I let off the clutch and give it some gas, a noisy grinding noise comes from up front of the car. The only time this happens is in first gear and only while in between releasing clutch and giving it gas. I'm pretty sure it's the throw out bearing, just need someone with more knowledge it confirm this for me. Also, if it is the problem, where can I buy a new one ?

engine/tranny: s13 blacktop sr20det
drivetrain mods: spec stage 3 clutch/ lightened flywheel, agency power steel braided clutch line, replaced tranny fluid with redline flupid about 5XXX miles ago