[Lynn]

I think that myth developed from the different Z/28 codes in 68. In 68 you could order with headers, that were, in fact, in the trunk and could be dealer installed.

The cross ram was pretty well known by the 69 model year, especially after Car & Driver did the 68 Z (with over the counter cross ram and over the counter 4 wheel disc brakes) comparison with a 302 Ford Tunnel Port engine Mustang. Lots of guys just assumed they could order the next year (69) with headers and cross ram. Of course, you could order both headers and cross ram over the counter, and there may have been a few dealers that would even do the swap for you, as the feds really weren't cracking down that badly yet.