ok while sitting still there is no noise in park or nuetral but when i shift into drive with foot on brake not moving, a rubbing noise happens and it is fairly loud.it is coming from the transmission area,since i am sitting still that means the rear end is not moving and drive shaft is not moving and the transmission is not moving .so i believe this noise is my converter rubbing against the inside of the converter which also explains why the noise seems to go away as i get going down the road.the transmission acts perfect,no slipping,i dont hardly feel anything when it shifts unless i am getting on it.sometimes while sitting there i can shift it back and forth a few times and it will quit making the noise.it is a 75 camaro with a 350 engine and going by the pan to the transmission the manual says it is a turbo-hydramatic 250 350 or 375b.i am not sure which they all have the same pan.i dont believe it is a cracked flex plate since it weems that would be a constant noise.what do you guys think.

 

check to see if the bolts are loose. mine did the same thing. also a noise that i had to establish once was my starter gear was getting hung up on the flexplate. i saw sparks coming from it. and i put a new starter in it. and it went away.

 

Ditto on checking the converter to flexplate bolts. I kinda doubt your converter itself is bad since it is shifting and driving like normal. You could even have a rattling/knocking from a loose exhaust for all you know. You might be able to see what's making the noise by looking under (not crawl under) the car while a buddy (someone you can trust) puts the car in drive and holds the brake pedal down.

 

update,replaced converter and the noise is gone,apparantly the needle bearings in the converter were shot.all is well.later