My rough calculations:
Mark X 3.0 : 250 bhp, 3400 lbs
estimated speed at end of quarter mile: 92 mph
Euro R: 215 bhp, 3000 lbs
estimated speed at end of quarter mile: 92 mph
It therefore will likely be a dead heat and will depend on the skill of the driver, the mechanical condition of the cars and the other factors such as weather and road conditions etc.
I think @Born2Race already gave the correct answer, although by a different calculation than mine.