Buzzing Noise on auto 1990 GT gear change 1800 - 2200 RPM

[Tom77]

Happy Wednesday from the sunny UK. Hoping some experienced ears may be able to help - Please see/listen on attached video clip. There is a buzzing/vibration noise regularly as my engine hits 1800 - 2100 rpm before gears shift on my auto vert. Does this sound like a loose baffle in the muffler perhaps (they are old, original flowmaster 40s)? I'm hoping nothing more serious..
As always thank you, For this novice Foxbody owner and mechanic the help I get here is invaluable

 

[gkomo]

Thats an odd sound. Are you able to crawl under the car and see if one or both of the mufflers is close to the frame rail or driveshaft and see if its rubbing? Maybe that specific RPM creates just the right vibration and if the mufflers are close enough it finally makes contact with something and creates the noise you hear.

 

[Tom77]

Thats an odd sound. Are you able to crawl under the car and see if one or both of the mufflers is close to the frame rail or driveshaft and see if its rubbing? Maybe that specific RPM creates just the right vibration and if the mufflers are close enough it finally makes contact with something and creates the noise you hear.

I will check first thing my morning tmrw, thank you!