I have dual Flowmaster 40s on my 302 (On it when I bought it) and for a cruiser it sounds nice and mean. On the freeway you can forget about having a conversation. So yes, Flowmaster 40s will get the job done. Here's a video of mine idling. It's hard to get a proper sense of the sound, though.
I haven't seen any comments on BORLA mufflers? My LT-1 with the good stainless pipes and two Borla's sounds great, but BRIDE wanted less noise, so added a pair of SUPER TRAPPS at the end and all is well. Quick removal and nice extensions brings back the sound I like.
Funny story, the fellow that did my exhaust does lots of exhaust work for Indy cars, plus street rods, and when I took my street rod to him it was a DRIVABLE chassis, no body. So I commented, this will be easy for you as you don't have to stand under and look UP. He said, you know, I just don't seem to do as good a job when I don't have the car on a lift, so I will build looking up. His welds are a piece of art, so small you can hardly see/feel.
I run dual 2.5" Thrush mufflers, they just call them "welded muffler" which are essentially a rip off of the flowmaster 40's. They sound just as good, and are 1/3 the price
The sound is nice, no drone or anything (on my setup at least) and they are fairly quiet when cruising, conversations are possible. But when you step on it, they really open up, it gets pretty laud.