If you want to retain the '73-'74 bumpers and guards, then I am pretty sure you will have to cut and weld your mounts to make it work. Well, you can bolt the bumpers to '72 rear mounts, but the inner bolt holes will be like a half an inch off. I had my back '74 rear bumper on '72 mounts with just the outer bolt on each side until I found a decent '72 bumper to use. If you're set on using the '73-'74 bumpers, I think it would be easiest to get '72 rear mounts and cut the inner bolt hole ear off and add metal to line it up with that hole in the bumper. I can't help you on the front end of the car yet, since I haven't done mine yet. I'm pretty sure I'm just going to have to get all '72 stuff as I did on the back. Like was stated above, I think the subframe will interfere with pushing the front bumper mounts back far enough. I hope all this rambling helps you out!