I just ordered a 1985-up bumper cover for my 1984 car. I personally like the cleaner lines of the later models and the 'air dam' will blend nicely into the IMSA front fenders.

Can I reuse my '84 bumper reinforcement with my new cover?

Also, is it possible/advisable to stabilize the back of the bumper cover with some polyurethane insulating foam? The top of the cover between the parking/signal lights and the centerline has a tendency to go concave with age. This has happened with this car and it was starting to happen with my ex-86.

 

I'm pretty sure the bumper impact bar is the same but I'm not sure about the impact absorber.
Not sure what the insulating foam would get you. You may need to back it up with something.

 

Thanks for your answer. I've been advised to use chicken wire or expanded aluminum mesh as a matrix for the polyurethane foam. I will do some research in the aviation sector. They use a lot of 2-part polyurethane foam in homebuilt aircraft construction.