How to keep the red devils and lose the rap

[74RR]

Hi guys. I've got a 74 RR with a 440 4speed with a mild cam. It's not red devil mufflers coming off of exhaust manifolds. The car has a great rumble at an idle, and also at lightly putting your foot into it. But when you really step on it the rumble turns into an ear pearcing rap. I'd like to keep the mufflers and wanted opinions on increasing the diameter of the tailpipes, if that would help soften and remove the rap. 20 years ago I was all about the rap, now I just want the rumble. Thoughts? Ideas?

 

[493 Mike]

I would recommend resonators in the tailpipes.
Mike

 

[Dan64]

^^^ What Mike said plus you could add a "H" pipe if you don't already have one.