i just put in a pro 50 sifter and ran the car at the track today i on my 3rd run i started to here a sound like a ratal but dont see any thing under the car it also sounds like a winding or slite grinding noies in 6th at hiway speed if i drop the clutch and i dont mean dumping it in 3rd 4th or 5th it makes a clunking sound any ideas what it could be?