Is there a way I can make this work> I just pu on hooker 2055's and the y pipe, now i realize i shoulda got the 2.5 inlet muffler, not the 3 in. What can i do??

Yea they make adapters to fit 2 differentized size pipes together. I know they have them at pepboys but im not sure about 2.5-3, they usually carry smallers ones. You can get one at an exhaust shop or they can make you one.

Adapters will work for you.