You do have to use the rubber mounts. You can hear it when you turn the key on, I can't hear it when the engine starts and I'm running a Dynomax Hemi Super Turbo which is louder than stock but not a Flowmaster.

Looking in my latest Summit catalog I see an Edelbrock pump that's supposed to be a lot quieter than your average electric pump. You could try that, I suppose. But the Carter is quiet enough for me. I'd definitely buy another.

R.