the angle of one or both exhaust manifolds. I contacted Waldron's Exhaust and ask the same question. The reply said that 1966 390 Fairlane H-pipe was a one year only part. They didn't elaborate on the exact difference. It is possible to make a 67 fit (I have heard) but I don't know what is required. Big hammer and big arms probably. Scott66gta used Waldron's and said they made a perfect fit for his 1966 GTA. Price was $280 (I think) for the H-pipe and about 3 weeks to manufacture it. It was around $600 for a complete exhaust system. I think I must have deleted their e-mail. I couldn't find it. Here's the link to them
http://www.waldronexhaust.com/
Good Luck and let us know what you do. If a 67 fits, they are cheaper and more available. I see them on Ebay all the time.
Murfman66
