Catalytic converters

[99 Red Rocket]

Installing a new full 3" catback exhaust system but my stock catalytic converter needs to be replaced and I was wondering if I should replace it with a 2.5 inlet/outlet catalytic converter or a 3 inch to match the exhaust system

 

[2gGst98]

You can try something like this

http://www.amazon.com/Outlet-Stainess-Exhaust-Extension-Adapter/dp/B00T3EVAAS/ref=sr_1_17?s=automotive&ie=UTF8&qid=1445046155&sr=1-17&keywords=2.5 inlet 3 outlet catalytic converters

My car came with one but I switched to a thermal and not needed anymore.

Make sure it's your size but, other then that you can call summit racing and they might be able to find you a 2.5"inlet/ 3" outlet cat. Good luck

 

[TehRiceBandit]

I would recommend a 3" high flow cat if your state allows it. A 2.5" cat will introduce a bottleneck.

Magnaflow makes a good hf 3"

Edit: forgot to ask, what downpipe do you have?