Hearing a rubbing sound?

Question

i have a 1989 Chevrolet Silverado and when i decelerate it makes almost like a rubbing noise and the faster im going when i decelerate its even more noticeable...now it has a brand new tranny, engine and rear end...my brake line does have a leak and i do have air in the lines which im patching up and bleeding off tomorow...also there is a really high pitched sqealing noise thats almost impossible to describe...its only noticeable at high speeds and you have to really listen for it...my EGR valve is also bad which im replacing tomorow...i know quite a bit about vehicles, so please dont give me an answer if you really have no idea what you are talking about because i will most likely know that thats not the problem...any help is much appreciated!

Answer 1

My dads 95 silverado had a faint high piched sqweel that was the u-joints

Answer 2

put in neutral noise different -  tire tread?

rear axle bearings and rear axle seals make s it look like brake fluid leak (rear) L/R sides

high pitch sound - have some one out side on shoulder of road and drive by them and see if high pitch can be heard as you drive by @ high rate of speed as you notice it from inside the vehicle