my muffler i currently have on has dual outlets that are 5 inches from center to center. I want to remove the muffler myself since its just clamped on. my question is if i order a y pipe thats 4 inches center to center will my dual exhaust pipes be able to each pull in half an inch to fit the y pipe?

 

Couldn't you just drop the muffler and see how much play you have with them?