Yeah it was modified, Opel GTs didn't come with 454s stock. At 1863 lbs, they are ripe for stupid swaps. In it's time, it was labeled as the "poor man's Corvette".
My dad and I restored one while I was in high school. Fun car to drive, handled really well, 1900ccs of slowness.
Manufacturer Opel
Parent company General Motors Corporation
Production 1968–1973
2006—2009
Successor Opel Manta
Body style(s) coupe
Layout FR layout
Engine(s) 1078 cc straight-4
1897 cc straight-4
Wheelbase 2,415 mm (95.1 in)
Length 4,113 mm (161.9 in)
Width 1,580 mm (62.2 in)
Height 1,225 mm (48.2 in)
Curb weight 845 kg (1,863 lb)–940 kg (2,072 lb)
Fuel capacity 50 L (13.2 US gal; 11.0 imp gal)[1]
http://www.4x4offroads.com/image-files/1972-opel-gt-261.jpg
http://www.modifiedcars.com/pix/cars_large/20831_24385.jpg
http://3.bp.blogspot.com/_-l2C8nYmCV0/SOLH4fgFyhI/AAAAAAAACd0/beAwR4urBCA/s400/4c90_3.JPG
http://www.jaylenosgarage.com/images/your_garage/cars/8643_1236085134487ad4196f1b9.jpg
http://www.carandclassic.co.uk/uploads/new/574354.jpg
Anyone have $500?
http://www.lotustalk.com/forums/f162/73-opel-gt-sale-75927/