Flowmaster exhaust advice

I am looking to get a Flowmaster muffler installed on my 98 Expedition, and I would like some advice from anybody who has installed it on theirs. I am not going with the dual exhaust, I am just going to get the muffler, and a stainless steel tip to make it look nice. My problem is I do not want a muffler that will be too loud, I want it to sound nice, but I still want to be able to hear myself think when I am driving it. I think the 40 series will be too loud, and am thinking about the 70 series. Any advice would be well appreciated. Thanks.

I have a 99 Expo, and have gone through a lot of different mufflers. Had the forty the fifty series with duals. Sound great but was not loud enough. I thing the fifty to the seventy series will do fine for you. Not too loud but a nice little rumble. Now I have a glass pack and next I'm going to take off the cats so it will be loud as I want it to be.
Ace.