My experience with Jacks Auto has been just the opposite, as I find their prices to be better than others (such as Year One, etc.). I ordered the 1970 Challenger grille emblem from them but find that there was no way to get my hand behind the grille to attach the mounting nuts. They exchanged the emblem for one of the stick on fender type which I mounted and believe me, it's not going to fall off. They are a bit slow in responding at times, but their prices keep me coming back.
I have mounted the 1970 Challenger emblems on my front fenders as well as many others have and I think they look great. Since I have a Black Challenger, the emblems breakup the black color a bit and they are not too small as they have a real factory look to them. In fact the Factory will be mounting the same emblems on the retro B5 later in the year.
(my two cents)