Building a Gr4 replica

Here's the rebuild story of a 1972 euro GTS project I purchased in 2013.


The car is a July 1972 car. Sold by Claude Dubois in Belgium to Mr. Dambois in Liege but not much more is known about its early whereabouts except for a few funny stories Claude Dubois told me. The car then turned up in 1974 when it won the “6 heures of Visé” in the hands of Chavan-Falla. Then, apparently it was crashed at a hill-climb event and more or less totaled. As will be evident in this rebuild thread, the chassis was pretty damaged, both in the front and in the rear. Most of the outside body panels also needed to be replaced. According to the original archives in Modena it was originally silver/black and a genuine euro GTS. The only other information in the documents were receipts from 1973 for right rear a-arms, axle assembly and 10 inch wheel, so the car was in an accident sometime in 1973. Signs of that incident are still visible in the chassis.

The car then turned up in Sweden in the early 1980s. At that point it was a project and was further taken apart and probably at that point stripped to the metal by media blasting. The chassis has had rust repairs done in some of the usual places which I think was performed back then also. The project stalled and the car was sold 20 years later to another swede, in 2004 I think, which re-did some of the chassis work and restored all the suspension parts, brakes, interior and more. Then in 2006 it went to the first owner in Denmark which bought more parts and had more chassis work professionally done before selling it to its second Danish owner (the guy I bought it from). He invested A LOT of money in new parts, including a complete factory GT5S body kit, NOS narrow fenders, doors, fuel tank, Kirk Evans quads, tons of NOS small parts, stub axles, chrome trim, tail lights etc., etc. Except for a few minor pieces the car is complete and includes an overhauled ZF-2.

A 5S conversion was started by the last owner, but I did not want to continue in that direction. Since I didn’t have much money in the car my initial thoughts were to do a Gr4 build for historic racing but bringing it back to original euro GTS specs would be cool too. My heart says Gr4 but my brain and economic sense says original GTS. Would be kind of cool with a 1972 Le Mans replica.

So what needs to be done to the chassis?

Well, the chassis IS NOT TOO RUSTY. However some repairs have been done incorrectly and need to be re-done. I’m sure they are solid enough, they are just NOT CORRECT. So I’m basically drilling the chassis apart to redo these areas which include; the inner b-posts, outer b-post skins, outer rockers, rear suspension uprights and a few other pieces. In addition, all four fenders had been fitted with GTS metal flares, so the fenders have come off and will be replaced as well (came with the car). Also, the car has been quite severely hit in the right rear and left front in the past. Both ends has been repaired, but the rear subframe is still a little bend – and the left front need to be pulled and rebuild.

Feel free to comment along the way

Here’s a shot of the car when I looked at it first

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After some time in the garage I drilled off the rear fenders. Fortunately, the previous owner who installed the fenders didn't do a very good job, so they were easily removed without any harm to them or car.

They are now sold along with the front 5S fenders.

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Started work on the outer rocker. Again my friend Michael did an awesome job reproducing these in one piece. They are exact copies of the ford-era rockers. Although they look pretty simple in shape - they are not!! In addition to bending along the length they also taper towards the ends both at the top and bottom. They also taper more towards the rear compared to the front. Reproducing these required fabrication of several special tools.
Michael also added the original drains at the bottom.

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I finally managed to find some time to work a bit more on the chassis

Since I'm likely going to convert this car to Gr4 specs for track use, I wanted to reinforce the front suspension mounts.

This is what the std mounts look like on this car and all the 71-74 production panteras

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For inspiration on how to reinforce to mounts, I had to look no further than my other pantera. That car is a pre-production car chassis #1267. This car came from the factory with substantionally reinforced a-arm, shock and sway bar mounts.

From what I've been able to figure out, only the very first 286 cars had these add-ons (I may be wrong though).

Spot the differences ?? - I Count 9 reinforcementplates

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This is a shot from when 1267s chassis was zink treated a few years back. The entire rear inner structure is build up from many pieces in quite thick steel (2.5 mm in the uprights). The entire structure is all original as shown - no rust repairs. Compared to the "production" cars, with the stamped sections, the chassis seem to have been seam welded in a lot more Places from the factory (Vignale).

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quote:
did you make tracings of your templetes? (that could be shared?)


No - but it should only take me 5 min to draw them up and scan them if anyone would be interested. So far I only did the passenger side, but both sides are similar except laterally reversed
quote:
I have learned a lot, and your work is an inspiration to people like myself who have similar work to complete, although not on such a scale as yours.


It IS a huge Work - but I really enjoy it. As long as I have the other pantera to drive I don't have pressure to finish this one in a certain time.

I did start on the drivers side of the car. Here I finished the center rocker and fitted inner b-pillar:

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Continued re-doing earlier bad and incorrect repairs. Here the rear suspension uprights.

I purchased repair pieces from a US-vendor - and sorry to say, I cannot recommend that. These pieces are not right, way too narrow to fit the suspension tubes meaning that they have to be reworked to fit.

Decided to repair them, instead of reproducing them completely. Had to widen them about and inch to fit, and to make them look correctly like the original structure.

Here the difference in tube Width after welding on side of the upright

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With the rear finished I'm moving on the left front. It has had a hit in the past, and the repairs (as usual) has to be redone. The damage includes damage to the frame that need to be repaired.
Here I've removed the left topfender. I have a new one to replace the old

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Thanks for the comments - that's motivating. And I need motivation as there's still a long way to go.

In all honesty I look forward to finishing the metalwork. For me this is hobby - I'am not a professional metal worker. However, with a lot of attention to detail, patience, A LOT of time and a few of the right tools it can be done to a fairly high standard. Also, having a friend that can fabricate the more complex metal pieces (outer rocker and inner B-posts) helps too.

Like David fx has with his project XXXX, I'm beginning to form a vision for this car as well, allthough it's a lot more traditional and not so creative. Stay tuned for that.
I love to see threads like this. It empowers more people to try things. When they can visualize what is done, they are more likely to try something themselves even if on a smaller scale.

In every project it is only as hard as the hardest task. The difficulty is keeping perspective of the task.

I find that most people can do even some of the most difficult task; they just don't know it. "Will" and "interest" are of the most important required skills.

I find if I beet my head against the project long enough there is little one cannot do; but only if the will to do so exist.
Push, I know I've said it before it this thread, but gotta say again... "impressive work man".

For the record, I totally agree with Comp's remarks. For me it's always worked, visualize and do. Worst that can happen is the need to re-do. Sometimes I wished I had visualized longer..or even sought out more advise first. But threads like this are great to share.
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Originally posted by Push1267:

In all honesty I look forward to finishing the metalwork. For me this is hobby - I'am not a professional metal worker. However, with a lot of attention to detail, patience, A LOT of time and a few of the right tools it can be done to a fairly high standard.


Kristian, What is the right tools?
Anders, I basically only use a welder (MIG/MAG and gas-welding) and a metal bender, heat and a number of different handtools. As I said, for the very difficult fabrication that need an English wheel or other advanced equipment, I turn to a friend. However, the pantera is for the most part not too complicated to make parts for.

Got a Little Work in over the weekend.
Removed the lower front a-arm mount for repair, it had been replaced at an earlier time and had to be re-adjusted for the correct chassis measurements.

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Kristian,

You are doing an amazing job. I must say, I hope you are patterning all of these parts because it almost looks like you'll be able to construct a Pantera unibody from scratch by the time you're done! Thanks for posting your progress. It is great to see everything in such detail, so well lit and photographed.

Mark
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you'll be able to construct a Pantera unibody from scratch


Ha, Ha! I think not Big Grin

The only parts that were patterned are the outer rockers and inner b-pillars.

I'm actually almost done, now working on the last section of bodywork. I "just" need to finish the left front, re-mount the fenders and then the chassis is ready for the painter.

It's going to be the original Gr4 red - anyone know what color that was? Maybe the same orange-red that the ´71-72 production panteras recieved??
I decided to use the design of the early, early cars for the front box-structure reinforcement. This is one large bar, compared to the later smaller triangular pieces. This bar sits between the front a-arm mounts and also closes the box structure up somewhat, thus providing af stiffer and less flexphrone front subframe.

It's a true copy of the original design on #1267. I added several drains at the bottom. Here is the bar being fitted

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I have felt that front "box" would be subjected to the same abuse the rear member recieves from centerline floor jack lifting.

I don't know if it does given there are fewer reasons to lift the front end, but that is one area I would like reinforced during rebuild so it could be
Most of us concerned about chassis rust drill 1/2" OD holes in the extreme bottom of both legs of the 'horse-shoe' stamping that supports the A-arms as well as 3 more in each main rear frame rail. Drilling the chin piece below the radiator is a good idea, but due to the shape of this piece and the 2 degree nose-down rake recommended, the hole placements needed is not at the back but about half-way forward in the curved area. Leaking OEM thermostats and hoses have ruined many of these parts (now reproduced by Johnny Woods in England).
Removing the damaged support pieces.

These extra bars were actually added by Ford/detomaso after the first crash tests by ford - to protect against frontal impact and get the chassis to pass the impact tests. They are not present in the original design and fx #1267 does not have them. Thought about leaving them out for minor weight savings since they have no structural purpose in terms of chassis rigidity. In the end I left them there but did them in the thinnest sheet that I had.

Here I removed the damaged parts

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JFB, I'm not sure what box you mean, but yes, in the front, the factory Gr4s had holes stamped in the upper curved crossmember and the lower radiater support for fatique strength (and a little weight savings).

I thought about replicating this, however, since the structures are closed now, holes cannot be pressed/punched to create the edge thickening that is important for strength.

Drilling holes and then bending the hole edge may be possible using heat and a taper tool, maybe? Haven't figured out how.
No time to celebrate - moving on to the driver side center structure - need to fit and install the outer rocker. First some trimming of the b-piller and experimenting with adding strengthening and wenting holes on the rear part of center rocker and b-piller.

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Hi Push,
Looking good man.

"This may look easy, but it takes an incredible amount of time to make sure everything fit and align as good as possible"

You said it man...!! It's amazing how long it takes to make it right. And it looks like you are getting it right! Congrats on the progress. Thumbs Up!
I've started to accumulate the parts I need to finish the chassis for the painter. That included the gr4 flares, aluminum door skins, the roll Cage and the WHEELS.



Here are the Wheels - a set of 10 and 14 inch Gr4 Wheels !!! Crazy stuff. I need those (and tires) to set the fender flares.

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A Little bit of Progress over the last couple of weeks. Had to repair the driverside rear fender. Upper rear corner