I have a 01 silverado z71 with true dual exhaust goin to 12 inch glasspacks and I was wondering if i went and got a set of longtube headers would i have to get the y-pipe with it or is there something else that can be done to keep the exhaust i have now?

 

You should be able to connect the headers to your exhaust with a little modification. You can buy the pipe and clamps. Summit sells a kit with an assortment of bends, you should be able to get your exhaust routed to the headers fairly easily, climb under there and take a look, estimate what you'll need and give Summit or Jeg's a call.