Another option is the pypes system and have a set of pipes made to go from the stock manifolds to the x pipe...
440 with mufflers or 315 with out... all stainless... I have a shop that makes the down pipes for $125 a set, pypes told me they will be producing the down pipes soon... I am sure if you didnt care about stainless you could get the down pipes for $75 a set...

It would be nice if the tti was stainless...


http://www.lmperformance.com/26937/smb10...o-mufflers.html