Do you have a better pic of that car? I think the 270 trim is not right at the top of the fender...it's down about 1 inch or so, isn't it? For the fender turn signals to fit, the trim has to be right at the top of the fender.
Please correct me if I'm wrong.
EDIT: Here's a 270 4 dr. that I found on the 'net. Note where the trim is located on the fender....The turn signal housings won't work with that trim.