I bought the Magnaflow full 3" SS exhaust system for my 69. The Magnaflow mufflers are 14" with offset in and centered out. I want to install Borla XR1s but I see either a 12" or a 16" XR-1 muffler and it seem 16" would be pushing it under a 69 Camaro. I know allot of people are running these and would like to no what size they are and maybe see a picture if they have one.
Tony...... EVERY "turnkey" build here leaves w/ XR1's. We always use the 16" center in/out, but can not help you on a 1st gen since we havent done one yet
But I can say that you will definetly be happy with them.
Sorry I couldnt help more.
I thought I had XR1's but what I have is Borla 3" ProXS on Jackass and to me they are the perfect muffler. They fit the recessed area on a 69 Camaro perfectly, are quiet inside the car and quiet at idle. But at wide open throttle they are screaming. Scott can attest to how they sound from behind.