Hi guys, I have a 86 IROC and while I was under the car today to check up on it in its winter slumber, I started looking real close at my exhaust. I noticed that from the rear of the Cat and back I have a fairly large diameter pipe with NO OEM crinkle bends, even the tail pipes are the same way. I tried to read the muffler to see if it was anything special and it just had a bunch of numbers on it near the middle of it. I couldnt measure the pipes because I didnt have any materials with me. I have the 305 TPI with auto, did this exhaust come stock?? Or did the previous owner get some new pipes? I would just like to find out.... Thanks!!!

my guess is aftermarket, I haven't seen a manderl bend from the factory on the 4 that I've worked on.

Mine's a 85 TPI IROC, origional stock exhaust...3-in into and out of converter ( 4-bolt flange in front and rear of cat , same as on Corvettes at the time),from there back, all mandrel bent , including the 2 1/2 in tailpipes...muffler clamped at exhaust inlet pipe, welded at tailpipes...all stock!

my OE stock N10 cat back was all mandrel bent. very nice. too bad it rusted though, otherwise I would still have it.

I put on the SLP cat back, and noticed NO difference. except it's slightly louder.

wow, I was way off!!! samsonite

Well thanks for the responses guys! Oh hey Larry Burd, is N10 a RPO code? If so I will check for it next time I go to get my car for spring time...

The RPO code "N-10" opition stood for dual catalytic converters. As advertised by Chevrolet, this option was good for a cool 10 additional horsepower! Nice.