He sold his two Super Stock Mustangs late in the season 1972, and purchased a Pro Stock Pinto from Jack Roush and Wayne Gapp. He quit his job at Ed Martin Ford to race full-time. In his first Pro race, he finished second to Bill Jenkins at the final Supernationals of the 1972 season. Glidden had his first national win the following season at the U.S. Nationals. His 9.03 second pass, at a national record , was #1 qualifying time in the fastest Pro Stock field. He beat Gapp in the event finals. 1974 was his second full season in Pro Stock. He won three events including the Springnationals and U.S. Nationals. That season he set the record for the lowest elapsed time (e.t.) and the highest speed (8.83 seconds and , respectively) at a Division 3 event at Bowling Green, Kentucky. The feat earned him 400 bonus points towards the championship. He had an 8.81 second qualifying pass at the U.S. Nationals to lower his e.t. record, and beat Gapp in the final round. These wins contributed to his come-from-behind win to beat rivals Gapp and Wally Booth for the season championship.