I agree with you about the L6 head pipe design. How much of the stock pipe from the engine to the cat is left on the car? Are there any of the flanges used for the converter left? If the muffler thats on there now is where the cat used to be than all the muffler shop has to do is make up a pipe with a flange on one end to fit the new y pipe with bolts and slip over the piece of head pipe left after the current muffler is removed. You could even drive the car over to the shop with the Z28 exhaust allready installed by yourself,having them make the new pipe, remove the current muffler, and hook it up. Or you could just bring them the pieces and have them put it all on which will cost more $$$. I would not recomend having them make a new pipe and you put it on because it can be so hard to get the measurements right. Jay 6155
