I really don’t know much about this car. Story from Dad is that there was a hole in rules that would allow this car to run and win class in Super Stock/HA which they did at Indy in ’72.
Beyond that entry I’m not sure how much they ran this car.
The caption of the photo reads:
Although best known for their Ford Pro Stockers, the team of Wayne Gapp and Jack Roush actually drove a Cobra Jet-powered ’69 Ford Mustang in the early 1970’s in the Super Stock/H Automatic category.
Here’s another pic of the car that I found in my Dad’s files: