Does anyone know if the stock exhaust on the LT1 and LS1's are the same size? I think they are both 2 7/8" but I just want to make sure. Also will the stock pipe that goes from the ypipe to the muffler from an LT1 fit an LS1 or not? If I'm not mistaken the LT1's pipe is longer.

 

It's off a '94 Forumla so that'll be a single cat which is why I think the pipe will be to long. When I had my '94 Camaro I had to buy the extra S pipe for the loudmouth catback to make it fit.