Go to the Flowmaster website. They used to have sound bites of the different series mufflers. I have 50's on my truck and it is a low mellow tone that sounds like no other muffler. I have the 40's on my '95 Impala and they are a bit louder and more aggressive sounding (which I like too). They are one heavy-duty muffler also.
That's what I recommend,
Scott


Scott Ward

2 1948 1.5-ton Loadmasters
The red one and The snow pusher
1 1950 3100
1 1955.1 Chevy 6500
1 1954 Chevy 6500 2-Ton
1 1955 1st Series COE 5700
1 1963 K20 (454)
1 1964 C10 (350)
1 1951 1.5-ton Dump Truck
1953 and a 1956 Ford F800

Raising a teenager is like trying to nail Jello to a tree!