I think your right, a 2" choptop might be just the thing for the Pantera. I also think your right about the wider front end mentioned in earlier posts.

Having returned from the CFOG-i Osage Beach show, I too have cleared up the honey-dews, cleaned up the shop a bit, and finally got a weekend in on the Choptop Pantera. I'd like to use this thread to detail the build of that car. And since there have recently been a couple of "how to" choptop threads, I thought that might be a good place to start.

Bear in mind, the donor car for the Choptop Pantera was acquired several years ago for $400. It was an '88 formula "with a rod knock". I never saw it run, or even turn over. I started the choptop process several months before the Pantera project came into existance, but documented most of the critical steps along the way. So if some of the "how to chop" pics are dated, you'll understand.

By now, most of the chop is completed, and the bodywork will be able to start. Various other parts of the recipe have been accumulated and assembled, such as the Corvette rotors & adapters for the brakes, new calipers & stainless brake lines, new radiator, rebuilt ac compressor, new alternator, Ed Park's 4.9 wiring harness, rebuilt 4t60-e transmission, 4.9 crate motor, Allante intake, full poly, etc.. The entire drivetrain gets disassembled one more time, and everything gets sandblasted and either powder coated or por-15'd.

But this is where the choptop really started:
This is the '88 formula, up on homemade ramps. Great for under-car work like oil changes.

So the first thing to come out was the fuel tank. Best to clean it out and replace the fuel pump now.

At this stage, other goodies were removed like the coolant tubes and ac lines, and most of the interior was removed. I sat in the car with the seat in my favorite position and measured head clearance, with the stock headliner in place. If your doing a chop, do this, and write down your measurement.

Anyhow, the car was then rolled into the shop, and the cradle removed, along with most of the body panels. I left the roof panel and door skins on. Then I went to great lengths to level the chassis, front to back and side to side. The front end was setting on the wheels & tires, the rear end had the empty cradle reinstalled and was setting up on 4x4 cribbing, and I had a set of jackstands set up about in the middle.

After the chassis was leveled, permanent reference points were established.

Pip is being slow, so I'll continue tomorrow.

David Breeze

So, about 4 eyehooks were set in the ceiling to hang plumb bobs from. The point where a plumb bob touched the roof was etched onto the roof.

The above pic also shows jig blocks that were hotglued to the roof for a carpenters level to set on. This establishes front-to-rear level of the roof section. A similar set of jig blocks set the side to side level.

The rear window glass was removed and a jig board installed. This board stays with the roof section when it is cut loose from the rest of the chassis.

The above pic shows the jig board. It is screwed into the top roof section, and rests on the chassis "shelf" along it's bottom edge. The bubble level is hotglued on and sets level & square in two dimensions. As additional point locating references, the metal angle tabs on either side of the board are clamped onto the chassis.

So now we are set to start chopping the chassis. Working space is created by removing the engine, the chassis is leveled and setting rock steady, and we can take parts off the chassis and accurately put them back in place.

BTW, I'm sure there are many ways to execute a chop. I've never had the chance to examine anyone elses work, or ever seen pics of how they did it. I just tried to think every step thru before doing it, and this is how it was done.

More to come.

Before any cuts were made, the cabin was braced against folding in upon itself. These brackets were fabricated and bolted to the strut towers. The pipes are thick walled boiler pipe, and are firmly in place up against the front firewall. Note that the way the pipes run and the jig board is made allows total access to cutting & welding operations.

Considerable time was spent looking at how the windshield and it's support structures would move, when laid back. I decided where the pivot point would be, based on where the cuts would be. Given this, it looked like the bottom edge of the windshield would raise up as the windshield laid back. So, I removed the black windshield adhesive all along the bottom edge, and up to and just past the calculated pivot point.

BTW, the windshield of the donor was cracked when I got it, so it will be replaced. However, it was left in during the entire chop process since it greatly aids in keeping the chassis square, once a few cuts have been made.

And this was the first cut. All of the interior and door seal and supporting parts had been removed by now. I used a Sawzall with a 6" and a 10" blade.

More to come.

And this was the second cut, where the roof top will actually pivot and rise up, as the windshield lays back.

The third cut is really just an extension of the second cut. It follows a recessed channel in the underside of the roof and connects the two "second cuts". The roof metal is two layers thick, just behind the windshield. This cut is made with the die grinder cut off wheel. A plasma torch would sure be nice, but hey.

And a fourth cut was made. I had planned this car to have no sun roof opening, so I felt free to make this cut here. To me, for this project, it was the right place to do it. Obviously, if you wanted to keep your sun roof, you'd make this cut elsewhere.

What happens is the roof top also moves to the rear, as the windshield is laid back. So, if you want to keep the back window in its stock location, you will have to shorten the roof top a certian amount. Seems like it was about 1" to 1 1/2" overlap, after this cut was made and the widnshield was laid back. It looks like there is room to make this cut either in front of or behind the sun roof opening, but I havent done that. You need to consider attach points of the skins, etc..

As you can see, I used a rope to support the front half of the roof top, after this cut was made. The rear half is still quite sturdy and requires no support yet. But here on the front half, you will need to provide a support that will hold everything steadily, and it should also allow you to move the front half back and down, as you mate things back together, later on.

I

All of this can make cutting and bending and welding back together become complicated. Fierst thing I did was drill out the 42+ spotwelds holding in each of the inside corner pieces and removed them. These are later reinstalled.

That makes the inside look something like this:

Next, the cuts were made to chop off the top of the rollover structure.

It was removed with the jig board and level blocks and reference marks all attached.

That left the side panels, or upright portions of the rollover structure exposed. The top was cut off in a single cut, made just below the driprail.

Then the upper 4" of the exposed uprights was cut off.

At this point, a trapeeze was hung to support the front section of the roof and the windshield. Since those cuts were made, it is very esy to move this section around, and support is important. The trapeeze allows for position adjustments, and doesn't get in the way of other work.

This shows the three cuts made to the outside of the upright. The chop cut is on top, and the two lower cuts are to allow inward bending. You might be able to just grab hold of the uprights and bend them in, they don't go too far inwards. But making these slicing cuts in the outer layers allows very precise inward bending.

So now the main thing is to get the pieces back together. From the measurement I had taken earlier of head clearance, I determined how much I wanted the roof to drop. I had cut about that much out of the uprights, but they are on a slight angle, so 4" off the sides doesn't really mean 4" of lowering. Close though.

So I went thru a process of cutting down the height of the jig board which is still attached to the roof section. First, I cut 3.5" off the bottom of the board and tried mouting the roof. But the sides still had room to come lower. I put the seat back in and double checked. Then I cut another 1/2" off the jig board, and things started looking just right.

Considerable time was spent getting the top leveled, and the windshield laid back square. Now's when it pays to have taken several reference point measurements. I wanted the door window frame to match, and the back window to remain in it's stock location. Finally a few tack welds were made, the seat put back in, and all levels and reference points checked again.

All of the numerous cuts or slices were examined for the best way to weld them back together. I cleaned them up for welding and cut patches, or cupons, mostly of 16 gauge steel. I wanted to cover each cut with an oversized patch. In some instances I used 1/8" steel for the patch.

After the outside was patched, I cut a big closeout panel of 16 gauge. Here it is shown half way installed. There is still a whole second half to go in.

The cuts made under the top of the windshield, and the cuts to the sunroof rail were reinforced with 1/8" steel on the inside, and 16 gauge on the outside.

This is the section removed from the uprights. It now measures 3.6" , the cut lines I laid out were 3.75" apart.

This is the 16 gauge steel patch welded onto the top of the #2 cut. Sorry for the pic quality. The 16 gauge steel shapes easily to follow contours. And it measures as thick as or actually thicker than most of the sheet metal of the Fiero chassis. I've been using .030 wire and argon/co2 gas and found in most instances you can weld right on with it. If you happen to have gotten to agressive with the grinder removing paint or scale, the base metal may thin a bit. In those cases, .025 wire does nicely.

And this is another set of 16 gauge patches, over the sunroof cut. With most of the oversized patches, you can weld the patch on from one side, and the weld the edges of the actual cut from the other side.

This is the underside of the #2 cut. Here I used several patches made of 1/8" steel, from an abundance of caution. The big hole is to access the roof skin bolt, and the small hole is a pilot to locate the center of the sunshade cutout. Also, you can see the 1/8" strap steel welded into the channel where the cross-cab cut is which connects the #2 cuts. The 1/8" steel welds very easily onto the Fiero chassis. I use a weaving side stitch sort of welding pattern, maintaining penetration and the puddle on the 1/8" side, and fanning into the chassis side. Works well. Where necessary, the heavier beads can be smoothed out with a 4" grinder.

And this is the same thing going on with the underside of the sunroof cut.

What can I say?

To me, the whole Pantera body, front & back, just begs for customization. And since it's made from stout fiberglass stock, it's easy to do those mods.

The current price for a full kit has been explained a couple of times earlier in this thread. Those prices will be good untill Carslile Kitcar 2006, when the prices may change or become turnkey only.