AdamMeh

I have a fiberglass '73/'74 front bumper cover that I would like to put on our '77. I will be glassing in the seams as well.

Since the '73 style doesn't have the same shape, I need some advice on how to fill the gap at the top center where the cover meets the body?

Here you can see the '73/'74 style (it's blue) and the cover from our '77.





Thanks in advance for any help.

Adam

DUB

****PROFESSIONAL OPINION****

I have mentioned this and OBVIOUSLY it is your car and you can do as you wish....BUT

First off....get the correct design bumper. Unless you just want to put major hours into this bumper.

YES...you can pull a splash mold off the original bumper where you need the missing bumper area...then.....laminate up a part from that mold...then laminate that part to your 73-74 bumper. Is it possible....YES.....would I do it...NO. Could I do it....YES. Would it cost more than getting the correct bumper...YES.

Even after getting this all done. And you did everything the BEST you can...only to find in a short time after it is painted that a ghost line appears or even a crack at the bottom of the fenders at the valance panel....or worse yet...across the top.

Secondly...bonding in a front bumper and having it NEVER give you ANY problems...is really, really, really, really hard to do. There are variables, forces and the way the front clip is secured to the impact bar assembly at the top outer points can create a bit of 'DRAMA'. Especially if this car is to be driven and not in a museum.

Please stop and think about this. Once again...do as you wish. But if you stop and think about this. Just as an example....if you have an 1/8" thick extruded aluminum angle . And you looked at it from the side. It would be a constant thickness with a 90 degree precise angle in it....correct???. It would look like a '7' from the side. That is what your front clip looks like. Basically a consistent thickness of body material. Then take that same 1/8" aluminum and cut it and place it against the other angle ( backwards '7'). SO now...these two pieces together are making up the side view of when your bumper is attached to your front end. You have the flat mounting surface ( vertical run)where the bumper touches the flat surface of your front clip ( other vertical run)...and the angles to the left and right are the top surfaces of the front end and the bumper. Kinda like a '7' and a mirror image of a '7' together.

NOW....when you go to get these two together.....EITHER you have to add material ON TOP of the seam...and blend it in...which will take quite a bit of material to do this all the way across the front end and down the sides.....OR you grind and taper the seam....which then would WEAKEN the angle due to taking material out of a needed strength point....which is the point on the angle aluminum where it makes a 90 degree bend. You would be removing material at this critical point.

Going in on the backside of the front clip and adding material so you can grind it back is possible....but it would require removing the metal strip that is bonded and pop riveted to it for strength. The SAME would also have to be done with the fiberglass bumper...to make sure that the 90 bend at the flange is strong enough.

DO as you wish and I truly wish you the best in this.

DUB

AdamMeh

Thank you very much for taking time to answer this DUB.

I should have given a little back story on the cover. The reason for using the '73/'74 style cover is because I'm not a fan of the huge bumper guards on the '77, so that's where all of this started. I also like the center grill section of the earlier style (we don't need a front plate here in AZ).

I think I understand what you are saying with the mounting surfaces, and the example you used. Again, thanks for taking time to explain not only the project, but the risks.

Adam

DUB

I can completely understand wanting to modify the front area to suit what you like. And if you are doing it...then it is up to you...but something else to consider.....so this possible design change does not come back and bite you is that IF you do away with the front section where the license plate would go...so you can install a grille.. You would be altering the safety impact equipment....which may not be a big deal so some people....but your insurance company may have different views on it. Doing this type of work for a living I always and to consider liability and safety components that a customer wants to alter or remove. Just 'saying'. Knowing that you would not sue yourself if an accident happened and you got hurt....but the innocent passenger sitting in the passenger seat just might go after you....especially if their attorney started 'digging around' and found that the cars safety structure was altered. And this Forum being part of the evidence of intent. I recently had a customer who wanted me to remove his sun visors because he did not want to spend the money to keep them from flopping down...and I told him... "Not on your life....either replace them...or do it yourself...or find some fool that will remove them for you...BUT not me."

DUB