David , if you have a 67 ,is it numbers match or...If it is I wouldnt just put a 'cooler' speedometer in...and if I remember right they look the same , thatr is blinkers are same location, idiot lights too, but Im` not sure if its same 'fit', size...? someone else may...
lots of body parts are different on the 67/68 cars ( even though the main shape is the same..), just look at fenders vs. turn signals, etc...inside for instance , console had ashtray in 67 ,not in 68 , the rear armrest ashtrays different size etc...( I just learned this...lol)