IMO every car is a little different. A combo that drones on one car may not drone on another car. And what fixes drone on one car may not fix it on another.

That said....my 70 RR with a 440 and flowmasters droned like crazy. I made a switch from an "H" crossover to an X pipe and the drone disappeared--no other changes. shruggy

Some guys I hang out with also used glasspacks as resonators near the tailpipe for this purpose with mixed results.

Last edited by wingman; 12/03/21 09:20 AM.
1969 Dodge Coronet Super Bee 383 A4
1970 Plymouth Road Runner 440 FC7 (sold)