Van exhaust?

Dynomax 17741 is a 6" round body muffler with 2-1/4" offset inlet/outlet and a 14" long body. That will probably work for you.

Dynomax 17777 is a 2-1/4" in/2" out oval body muffler with an 11" long case. Probably the best choice for a car.

A muffler shop can bump up a stick of 2" to slip in the 2-1/4" outlet of the round body muffler. That's the way I'd go for your van. If it's still too loud I'd add a glasspack in the tail pipe for a resonator.

The bends of a tail pipe going up over the axle, back down, and then out the side (5 bends all 45° or greater) will significantly quiet the tone over any other configuration.

Looks like all of the larger/longer body Dynomax mufflers are 2-1/2" pipe and up. I like the 17741 for your application though.

All the Super Turbos have the same size internal tube as the inlet up to the 2-1/2" pipe size. The 3" inlet mufflers have 2-1/2" internals.