I have owned both, and was amazed at how differently they rode and felt. My only big gripe with the '67 was every time I got out of the car, I cut my shoulder on the sharp tip of the vent window. It may have just been the goofy gangly way I get out of the car, but I bet I drew blood a dozen times in the two years I was driving it. Cosmetically, I like the rear marker lights and deluxe interior of '68 much better than '67. Driving wise, the '67 seemed a bit smoother, but the 326 definitely did not have the pep my 400 has. Maybe a 326 HO would be a bit better there. The '68 350's had more pep, but not to the degree of the 400. For overall cruising, ALL models are great! The mono leaf rear suspension was also a bit stiffer for '67.
It all comes down to colors and taste. I'd take any of them over a 'Maro any day!