My completely stock 50,000 mile 1968 Formula S notch ran a best of 14.2 at I think 98 MPH. I am sure about the ET, not as sure on the MPH. It was a long time ago. The car had 3.23 gears and 185/70-14 radial tires and didn't spin at all.
This is probably the next best account after the magazines from the 60’s. If it was 98 mph and around 3,200 lbs that should be about right for ~275 crank hp.