73 and 74 bumper guards are different. The 74s are much larger then the 73's. I accually like the look of the 73's but 74's are just over the top IMO. As Jamie said, they are normally removed. It shouldn't be too hard to find some decent used ones.
I'm not 100% sure but I think the little rubber wedges that go from the guards to the valance are the same for both years. Don't quote me on that though.