That video shows the Rats omega. Rats being a Norwegian automatic transmission company, and the car is their showcase, albeit with a manual box but anyway, they chose the omega for it's aerodynamic shape! Could have had any car they wanted, and likewise any engine they wanted, in this case a Lexus v8!
They tuned the lump, to just short of 1000 hp I believe, and built a transmission to handle that power, which was the point of the project and their business.
The Rats web site shows the story in more detail, and where they had to cut and re weld the chassis to make it fit, with a steering rack from a Nissan as the old steering box was in the way.
To me a very interesting part of that video is how little steering input is required to get it round that oval. Although the surface will be billiard table smooth I would think, no lorries rolling round the outside lane at least.
Anyway, Gm's canned v8 project was a straight fit. Special parts, including exhaust manifolds and steering box oil cooler where needed, and I reckon the real reason the project failed lies somewhere in the those parts, and nothing to do with restricted coolant ways in the ls1 lump as I believe was claimed.