Tell you the truth, I don't even know, I just went in to CE Franklin with the exhaust end that bolts up to the manifold and picked two elbows that would work for me, I could look at my bill if you want to know the exact measurments, I think they were either 2.5 or 3in 90s and the thickness is around 1/8 thick, maybe a bit thicker? Cost me a whopping 6 bucks
Thanks,
Deny