So the flanges on the ends of both the cat and the intermediate broke off due to rust. There is no other rust holes anywhere, so I don't need to replace the cat and pipe...

Rather than trying to weld on new flanges, I just want to put another pipe through the two (after using a hacksaw to cut the bell shapes off of the ends). Does anyone know the size of the interior of the pipes so I can connect them together?... i can't measure myself unless I cut the bells off, which i don't wanna do yet

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Forgot to add... 96 Ranger 3.0 engine