Review on Walker 21683 Muffler by Nick Singh

The muffler appears to be well made. The sheets are thinner than OE and lighter compared to OE. It is also 1 inch shorter than the original muffler. It is not clear which end is the input and which is the output. "INPUT ->" is stamped in the center of the muffler (the arrow is deceptive: the direction of gas flow or is the arrow pointing to the input?). I had to check the manufacturer's website which shows the inlet is a large tube (67mm OD). For me, this "straight fit" turned out to be a science project: Since the muffler is shorter than the original, I had to buy 3 inches wide. Clamps for butt and lap joints. Intake muffler OD is 67mm/ID is 63mm, Buick enclave gas pipe OD is 63mm. That would be a straight fit, but the muffler is too short so I had to use stainless steel. Butt splice clamp (EVILENERGY 2.5"). The muffler OD is 61mm (why is that an odd number?), the Buick Enclave gas pipe OD is 63mm, so I had to use a stainless steel butt splice clamp (EVILENERGY 2 .5" that don't due to the difference in 2mm muffler 61mm / pipe 63mm they don't close perfectly. My recommendation to the manufacturer would be for a good butt joint to size the outlet to 63mm. And to lengthen the inlet by 2". (so the muffler inlet really "fits straight" and goes through the Buick Enclave's 63mm OD pipe) I used aluminum tape under the clamps to seal the gas.Only 50km driven so far so good.