I have been looking to replace the muffler on my 1986 911 Targa. I have found several aftermarket SS mufflers that look like they will fit. They are 13-22 inches long. They would go straight out from the cat. You will need ot add a Porsche style flange to connect to the cat or test pipe. Has anyone out there tried this before? Any suggestions. These mufflers are all less than $200 each.