Originally Posted by pitts64
Thanks Pugsy.. Which ones do you have?
Hold it, sorry. I just remembered. With my 327 I had a drone sound coasting down around 1200 RPM's and lower. When I swapped the 5.3, it was good after that.
Thrush, 2-1/2" about 24" long.
The 327 had stock cast iron manifolds.
The 5.3 has 2014 Camaro iron manifolds.
Not sure if it was the manifolds or the engine that took away the drone.