This thread shows the procedure I have used to modify early/mid 90's GM C/H body strut tower braces to fit A body cars.
The first step is to obtain a stock strut tower brace from an early/mid 90's C or H body car. I believe these platforms include the Buick LeSabre and Park Avenue, Oldsmobile 88 & 98, Pontiac Bonneville, Cadillac DeVille, and possibly a few others. The stock strut tower braces from these cars consist of a 1" square steel tube center section with a couple of bolt-on end pieces that attach to the strut towers.
Here's a photo of one of these bars in stock unmodified form:
To adapt these C/H body strut tower braces to an A body car, I modify the end pieces so they bolt up to the A body strut towers, leaving the center square steel tube section unmodified.
Note that GM changed the A body strut tower bolt pattern sometime around 1990. The bolt pattern itself is actually the same but it's rotated / clocked 90 degrees different on the newer vs. older strut towers. The majority of the photos shown in this thread are for the 1990+ pattern.
I start off by making a couple of cardboard templates. These photos show both the left & right templates being test fit on one of my parts cars:
At this stage, a bit of experimentation with the cross bar placement is necessary to make sure the bar will clear various obstacles in the engine compartment. Some things (just to name a few) to watch out for are not blocking the master cylinder cap, not interfering with the auto trans dipstick, not hitting the power steering reservoir or blocking the cap on engines like the 3.8L & 3300, and not hitting the alternator on engines like the 2.8L & 3100.
Once the cross bar placement has been finalized, I transfer the cardboard templates over to some 12 gauge or 1/8" steel plate. The steel plate can be cut with a metal cutting blade in a sawzall, a cut-off wheel in a grinder, or (if you're lucky enough to have access to one) a plasma cutter. The following photo shows the rough cut steel end pieces fit into place on the strut towers along with a (currently un-modified) C/H body bar laying in place on top:
And a couple more close-up photos of the same thing:
Note the lines drawn on the C/H strut tower brace ends with a silver sharpie ... those are where the ends will be cut so they can be welded to the home-made end pieces that fit the A body strut towers.
At this point, the home-made end pieces are just in rough cut form and need a bit more work to fit them to the strut towers. I start by bending a curved lip on the end pieces. This serves 2 purposes. One, it gives the ends a factory-fit appearance up next to the raised center of the strut towers. And two, the curved edge adds some rigidity to the metal. I don't have any fancy tools for making such bends so I simply use an adjustable wrench with the jaws closed up tight enough to form a snug fit to the thickness of the metal. Then work slowly back and forth across the area to be bent, making small bends each time. This procedure takes a little bit of practice as trying to bend too much at a time will often result in a rough / wavy edge.
Bending the curved lip on the edge:
And here is a photo showing the LH end piece after bending along with the RH piece that has yet to be bent:
As seen here, bending the curved lip on the edge gives a snug fit up against the shape of the strut towers:
At this point, one more bend is necessary to compensate for the inward tilt of the strut towers. I measure in about 11" from the edge of the car's fender and mark a line along the end brackets. Then using a similar procedure (bracket clamped in a vice and a couple of larger adjustable wrenches), I put a slight bend in the bracket so it can follow the tilt of the strut tower while allowing the center bar to remain level:
Now that the home-made end pieces have been cut and bent to fit, it's time to mark out where they will mate up with the C/H body bar. With those end pieces bolted in place on the strut towers, I lay the C/H bar in place. Note that the unnecessary C/H body specific outer ends have been cut back (as pointed out in an earlier photo with the silver sharpie markings).
Once the placement has been marked, the home-made end pieces can undergo a final trimming to mate them up with the cut-off outer ends of the C/H bar:
The next step is to tack weld them together. Note that I sand blasted the old paint & rust off the metal in the areas to be welded.
After tack welding and making sure the fitment is okay, I weld them solid:
Although they could be installed at this stage, I like to finish them off for a smoother appearance. That involves carefully grinding down the welds so they're flush with the surrounding metal. Then I sand blast them to remove any remaining old paint or rust. Next I use a thin skim of Evercoat glazing putty (it's like thinned out bondo) to cover any grinding marks and small divots left in the metal from bending the curved edge with the adjustable wrench. Finally, a coat of primer and semi-gloss black paint gives them a factory like appearance.
Here is a bar I made a while back for my 88 Cutlass Ciera ... it's getting a bit dusty & dirty already
In this photo, I am holding up the cardboard template that was used when making the end pieces. As mentioned earlier, these look a bit different because they're for the 89 & earlier strut tower pattern.
And to illustrate the early / late strut tower clocking difference, here is that same template being placed on a 92 strut tower ... to make it line up with the bolt holes on the RH tower, the cross bar would have to be pointing toward the front of the car (or to the rear to make it line up with the LH tower).
Finally, here is a pic of the finished bar in Mom's 94 Cutlass Cruiser wagon with the 3800 swap:
The first step is to obtain a stock strut tower brace from an early/mid 90's C or H body car. I believe these platforms include the Buick LeSabre and Park Avenue, Oldsmobile 88 & 98, Pontiac Bonneville, Cadillac DeVille, and possibly a few others. The stock strut tower braces from these cars consist of a 1" square steel tube center section with a couple of bolt-on end pieces that attach to the strut towers.
Here's a photo of one of these bars in stock unmodified form:
To adapt these C/H body strut tower braces to an A body car, I modify the end pieces so they bolt up to the A body strut towers, leaving the center square steel tube section unmodified.
Note that GM changed the A body strut tower bolt pattern sometime around 1990. The bolt pattern itself is actually the same but it's rotated / clocked 90 degrees different on the newer vs. older strut towers. The majority of the photos shown in this thread are for the 1990+ pattern.
I start off by making a couple of cardboard templates. These photos show both the left & right templates being test fit on one of my parts cars:
At this stage, a bit of experimentation with the cross bar placement is necessary to make sure the bar will clear various obstacles in the engine compartment. Some things (just to name a few) to watch out for are not blocking the master cylinder cap, not interfering with the auto trans dipstick, not hitting the power steering reservoir or blocking the cap on engines like the 3.8L & 3300, and not hitting the alternator on engines like the 2.8L & 3100.
Once the cross bar placement has been finalized, I transfer the cardboard templates over to some 12 gauge or 1/8" steel plate. The steel plate can be cut with a metal cutting blade in a sawzall, a cut-off wheel in a grinder, or (if you're lucky enough to have access to one) a plasma cutter. The following photo shows the rough cut steel end pieces fit into place on the strut towers along with a (currently un-modified) C/H body bar laying in place on top:
And a couple more close-up photos of the same thing:
Note the lines drawn on the C/H strut tower brace ends with a silver sharpie ... those are where the ends will be cut so they can be welded to the home-made end pieces that fit the A body strut towers.
At this point, the home-made end pieces are just in rough cut form and need a bit more work to fit them to the strut towers. I start by bending a curved lip on the end pieces. This serves 2 purposes. One, it gives the ends a factory-fit appearance up next to the raised center of the strut towers. And two, the curved edge adds some rigidity to the metal. I don't have any fancy tools for making such bends so I simply use an adjustable wrench with the jaws closed up tight enough to form a snug fit to the thickness of the metal. Then work slowly back and forth across the area to be bent, making small bends each time. This procedure takes a little bit of practice as trying to bend too much at a time will often result in a rough / wavy edge.
Bending the curved lip on the edge:
And here is a photo showing the LH end piece after bending along with the RH piece that has yet to be bent:
As seen here, bending the curved lip on the edge gives a snug fit up against the shape of the strut towers:
At this point, one more bend is necessary to compensate for the inward tilt of the strut towers. I measure in about 11" from the edge of the car's fender and mark a line along the end brackets. Then using a similar procedure (bracket clamped in a vice and a couple of larger adjustable wrenches), I put a slight bend in the bracket so it can follow the tilt of the strut tower while allowing the center bar to remain level:
Now that the home-made end pieces have been cut and bent to fit, it's time to mark out where they will mate up with the C/H body bar. With those end pieces bolted in place on the strut towers, I lay the C/H bar in place. Note that the unnecessary C/H body specific outer ends have been cut back (as pointed out in an earlier photo with the silver sharpie markings).
Once the placement has been marked, the home-made end pieces can undergo a final trimming to mate them up with the cut-off outer ends of the C/H bar:
The next step is to tack weld them together. Note that I sand blasted the old paint & rust off the metal in the areas to be welded.
After tack welding and making sure the fitment is okay, I weld them solid:
Although they could be installed at this stage, I like to finish them off for a smoother appearance. That involves carefully grinding down the welds so they're flush with the surrounding metal. Then I sand blast them to remove any remaining old paint or rust. Next I use a thin skim of Evercoat glazing putty (it's like thinned out bondo) to cover any grinding marks and small divots left in the metal from bending the curved edge with the adjustable wrench. Finally, a coat of primer and semi-gloss black paint gives them a factory like appearance.
Here is a bar I made a while back for my 88 Cutlass Ciera ... it's getting a bit dusty & dirty already
In this photo, I am holding up the cardboard template that was used when making the end pieces. As mentioned earlier, these look a bit different because they're for the 89 & earlier strut tower pattern.
And to illustrate the early / late strut tower clocking difference, here is that same template being placed on a 92 strut tower ... to make it line up with the bolt holes on the RH tower, the cross bar would have to be pointing toward the front of the car (or to the rear to make it line up with the LH tower).
Finally, here is a pic of the finished bar in Mom's 94 Cutlass Cruiser wagon with the 3800 swap:
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