Don ran some SCCA races in 71 but in that article he was probably talking about 1971 IMSA GT racing. IMSA had a new six race program that was promoted as a GTO Corvette vs GTU Porsche battle. Some were long races requiring a driver change. Don was co-driver for the Dave Heinz car and Bill Schumacher car. Heinz was the top Corvette team and won its class and Don and Dave won the Daytona race. Don was 3rd in driver points for 1971. The Heinz Corvette is the car no. 57 well known Corvette race car with the wild rebel flag paint job.
here is a picture of Don getting in the car at Daytona.
Under the pic is a Heinz racing shirt that is from the Yenko estate.
If Don was here he could have said "been there...done that....and got the tee shirt.....
