I have a 2004 Monte Carlo LS and I was wanting to put a ZZP Downpipe with cat in it to replace the old cat and and take out the u bend. Do these downpipes fit the LS Monte Carlo? If they do I will get one for my Monte. Thanks

 

The 3400 and 3800 downpipes are not compatible with eachother. Mounting points and such are different. Take a look at this thread, there is an answer to your question, a downpipe that should work for you Monte:
https://montecarloforum.com/forum/fw...p-power-46071/