You'd be fine with a '68 for an Eleanor-build as there really wasn't very much differences between the two.
The fake scoops on the rear quarter panel had two intakes on the '67 but only one on '68
![](http://www.musclecars.se/ovrigt/franabilar/franabilar_jpg/mustang_anders_01.jpg)
![](http://home.no.net/rinamf/c/data/upimages/fordmustang1968.jpg)
The dashboard is very much the same on the two also.
'67
![](http://static.howstuffworks.com/gif/1967-1968-ford-mustang-6.jpg)
'68
![](http://static.howstuffworks.com/gif/1967-1968-ford-mustang-14.jpg)
Don't think there was very much that differed in the engine room either but I don't know for sure so don't take that for granted.
Niclas