How to put way too much effort into dropping 20 lbs from your 4 eye
...By NIKwoaC
After owning my '86 for 13 years now, there is not much left about these cars that I don't know about. With that said though, I recently learned that in 1987, along with the aero-nose changeover, Ford also changed the front bumper structure from steel to a composite/fiberglass unit, which is a shade over 20 lbs lighter than the outgoing steel counterpart. I also learned that a handful of people have successfully converted their pre-87 cars to the fiberglass bumper.
SO I thought, "should be simple enough, right?" Well as it turns out, no, not really. But what the hell, I did it anyway, and here's the process:
Step 1: Hit the junk yard, find an un-crashed aero-nose Fox, and yank the bumper. Mine was cracked on one side, but not in a structural location, so I went with it, planning on just repairing the crack myself.
Repairing the crack-
Step 2: Pull the bumper cover off your car and remove the bumper.
Here's a shot with the fiberglass bumper sitting on top of the steel one for size/shape reference. Note the turn signals are integrated into the steel bumper... We'll address that later.
Step 3: Modify the 4-eye bumper shocks. As it turns out, the bumper shocks are completely different. The 87+ cars use a longer shock with a completely different mounting flange- longer probably to accommodate the aero nose cover. You can't use the newer shocks because it will push the cover about 1" away from fitting back onto the car.
New shock on the right. Note the stroke is the same, just the shock cylinder is longer. Please ignore the chaos that is my work bench haha.
Installed with the 87+ shocks.
You end up trimming a little off the top AND bottom of the 4-eye shocks to fit into the fiberglass bumper. I mounted the newer shocks in the car, measured from the floor to the top and bottom of the flange, then mounted the original shock, marked lines at those measurements and chopped them off. Make sure they're still level after you hack at them, and a little Rustoleum will keep the rust away.
Step 3.1: This was more of an optional step to satisfy my over-analyzing engineering brain. I made brackets from angle aluminum to "spread out the load" from the narrower '86 flange to the wider mounting surface of the fiberglass bumper.
I should mention at this point that you need to slot the mounting holes in the fiberglass inward to fit the narrower bolt pattern in the 4-eye shock flanges. Here is a shot with the bumper loosely bolted in place. If you want to use washers, you'll have to trim them to clear the bumper geometry, as you can see here.
Step 4: Mark and cut out windows for the turn signals. This takes some trial and error, fitting up the bumper cover, trimming a little at a time, and trial-fitting the turn signals themselves.
Since all this gets covered up by the bumper cover, I was not too particular about making the cuts look pretty. If you're super anal, you could come back and sand them smooth, but... Meh, this already took me long enough.
Step 5: Fab up mounting brackets to hang the turn signals. I used 1/8" X 1" aluminum strip. Sorry, my turn signal housings are pretty dirty in these shots.
Step 6: Hang 'em. Again, this takes some trial and error to get them to sit in the openings on the bumper cover where you want them.
So that's pretty much it, from here you can just button the car back up.
There are a couple of details that I may circle back around to in the future if I get REAL bored- but for the most part it's done. All in all, you could probably do this in a full weekend, assuming you did not need to repair it like I did, and you already had the bumper and all the materials. I did not weigh the aluminum parts, but I imagine it's a wash with the steel and fiberglass you remove.
I promise I'm still working on more significant stuff for the car- You can probably see the TKO parts on the workbench in a couple shots above, and 351 parts are still floating around the garage. Stay tuned.