I remember the GT.
It resembled a small Corvette.
Someone said they planned to drop a Chevy 350 in an Opel like your’s.
Don’t know how it turned out.
I always thought the GT was designed after the Corvette. It turned out it was the opposite. The Corvette was designed after the Opel. There was not a lot of room in that engine compartment for much more engine. Heck, one thing I loved about the car is that even though I’m over six foot, I still fit in it, but just barely. I was amazed, after I had owned the car for a couple of years, that the drive train tunnel is not in the center of the car. The passenger side is rather tight. :-)