This is not a conversion that I did. However I purchased a 3000gt that had this conversion done. The 3000gt was in rough shape (rusty underneath, no motor, had been rear ended hard) so I ended up parting it out. However since the targa conversion was so unique I decided to take a lot of pictures and document what had been done really well. I ended up cutting off the entire top section of the car and selling it as a targa conversion package to a guy in Mass. He'll be putting it on his track car along with a full cage setup.
What exactly is it?
A long time ago a member of 3si.org forum discovered that by utilizing Spyder hard top components you could cleverly create a hard top out of a 3000gt. DustinP was the name of the username of this 3si member. He was able to acquire 2 wrecked Spyders. He pulled off what he needed from one of the tops and converted his personal 3000gt into a targa. Then he tore the roof apart on the other Spyder and made a targa conversion kit that he sold for $4000. I believe the car I acquired was owned by the guy who bought his extra kit. Here are DustinP's old threads discussing the conversion:
Here is a pic of DustinP's old car. Pictures of the targa converted car I acquired are further down.
How Many Targa tops are out there?
There are only a few. There was this one that I parted. DustinP's original car is now owned by a member on 3si called 91red_stealth and it's still around. Mitsubishi's concept car that later became the released 3000gt was initially called the HSX and had a targa top in it's original design. I'm not sure how many concept cars were made and/or where they are. But they would have the targa. Jackie Chan even drove one in an old movie. There is another 3s member who also attempted making a targa without using Spyder parts and gave up when it came to trying to seal the roof.
How was this conversion originally done?
This list should give you a general idea of what was initially involved in this swap. I also have a Youtube Video below it which describes it further.
Start with a donor 3000gt and a wrecked Spyder
The rocker Panel area needs to be re-enforced to compensate for the roof structure being cut. This was done by removing the carpet, pulling the wiring aside, and welding a thick plate of steel the length of the rockers.
The donor car has it's front upper windshield portion cut off mid A pillar. The roof is also cut down the middle for now just to get the front portion of the roof out of the way.
The top portion of the Spyder windshield is cut off half way and welded onto the donor car. This way the front of the targa will latch just like the Spyder does for an oem fit and seal.
The front section of the Spyder hard top roof is removed from the hinge. This becomes the removeable roof.
Pins are fastened onto the back side of this removeable roof. These will be pins that eventually slide into the back of the car. The idea being slide the back part of the removable roof into the car, and then push the front end down to latch like the Spyder does.
The targa roof is carefully set onto the front windshield latch area that was welded over from the Spyder. The rear section of the roof is marked and cut. A special piece of bent metal (designed and sold by DustinP a long time ago) is attached (welded) at this cut to provide a spot to use a Toyota Supra rear targa seal on
Plates are welded to the back section of the roof with holes made in them to accept the targa pins
The oem window seals, interior A/B pillar trim, and exterior A pillar panels and sail panels are modified to accommodate the targa top
What did I sell in my targa package?
Basically I cut everything off my targa converted shell so that it could be applied to a cleaner rust free shell. This was a proven solution that had been on the road for 10+ years.
The front windshield section from this targa converted shell. I cut it towards the bottom. You can see where it was welded midway before. This contains the oem Spyder locking latch mechanism and inside Spyder plastic trim cover that the visors would attach to. The locking mechanism the Spyder uses is an electric motor. I tested the motor and confirmed it still works.
The removable Spyder roof section with rear pins already created and attached
The rear roof section cut off mid sail panel. This includes the custom bent metal piece and oem rear supra seal already attached.
The 99 sail panels that had the front tabs cut off to accommodate the targa
The front A pillar inside and outside trim that has been cut and modified for the targa