It depends on what Dynomax muffers you're talking about. The crimped together mufflers are virtually identical to a standard Walker Turbo. Unless Dynomax has redesigned the internal structure of their Super Turbos in recent years, theirs still neck down to 2 1/4 inside. https://board.moparts.org/ubbthread...ntthread/Board/21/main/99039/type/thread.html
