i was with a friend who has a blaster and sumthin started radeling around in his tranny when he is in first gear or neutral..its pritty loud too.the rest of the gears work fine and the motor runs fine...when the cluch is pulled in in first it makes the nosie even when its not moving

 

Haul the clutch cover off and see if anything is broken. Odds are its in your clutch and not the tranny.
Also somtimes when exhaust is leaking out of the header it makes rattle sound as to what you were describing. With it running push on the exhaust back and forth where it meets the flange on the cylinder. If you hold it over and it stops then that might be your problem.