1975 had seen a new Porsche domination and John Bishop wanted to put an end to that situation. That is why he created fhe AAGT category, a special category made for American built cars which allowed extensive modifications. Chassis would be tube-framed while engine could be bigger and cars could have wider tyres. This would provide more competition for victory at a relatively low-cost. Small teams could have a go at it, if they had the skills. The first car that found itself developed as an AAGT was the Chevrolet Monza which had all the potential for a real efficient development. Horst Kwech and Harry Theodoracopoulos had already entered cars in 1975 with mixed results. Mark Donohue intended to enter two cars with Charlie Kemp for the 1976 season but was killed at the end of the 1975 season. Charlie Kemp subsequently lost the deal to Al Holbert. This car, developed mainly by Dekon Engineering, powered by a V8 6,0L developing 580hp, proved immediately successful. In the hands of Al Holbert, it clinched the 1976 and 1977 title. (You can see him at Mid Ohio 1977 leading George Drolsom on a Porsche 911S)
Michael Keyser and many other racers entered similar cars for the following years. These drivers were Warren Agor, Brad Frisselle, Maurice Carter, Tom Frank, Jim Trueman, Greg Pickett and some others.
But other cars could be seen on the IMSA circuit from that period. One of the most spectacular was certainly Charlie Kemp's Ford Cobra II. Powered by a V8 5,8L engine, it was able to produce some good results as its best one, at the Daytona Finale where it took 2nd overall.
Carl Shafer too had begun to develop AAGT cars and ran a Camaro that took him to some good results. He became a well respected driver known for his soft-spoken language. Jim Moyer always campaigned wild looking Corvettes, as a private entrant, he never made it to the podium, but always was an honest contender. Rick Hay entered a Corvette from 1976 to 1979, and developed it as an AAGT car in 1978 and 1979. He obtained some interesting results but could not achieve his goals, as he passed away after suffering from leukemia. Later, Joe Chamberlain entered a wild looking Corvette that was not to accomplish feats too but such cars have always been a pleasure to watch on the track. Other drivers to enter AAGT cars were Rich Sloma, John Paul, Herb Jones, Roy Woods, RV Schulnburg, Carmon Salomone, Terry Wolters, Clark Howey and many others. Here, Clark Howey's Camaro is seen at the 24 Hours of Daytona 1978.
In 1978 and 1979, Glenn Bunch entered a radical Dodge Challenger that added a welcome diversity to the usual IMSA field, he scored some good results with his car. The car had a 6,9L hemi V8 given for 600hp and underwent radical changes as the races went on!
However, the Porsche 935 Turbos had remained unbeaten as they were constantly developed and the AAGT cars finally found themselves outdated. Later, in 1981, the GTPs accelerated their slow dive but you could find AAGT cars until 1986.