Conover, a 53-year-old from Roosevelt, Utah, had three birdies, two bogeys and two double bogeys in the third round.
Jim Hicks, a 56-year-old from LaPlata, Md., is alone in second place, four back at 17 over.
in other flights:
Senior Hogan Flight (handicap 8.0-11.9)
Don Miller, a 65-year-old from North Bay, Ontario, carded a 7-over 79 Thursday on the Stadium Course at TPC Sawgrass to grab the lead by five shots over Richard Lipoccolo (87).
Senior Sarazen Flight (handicap 12.0-15.9)
Mickey Rogers, a 57-year-old from Mt. Pleasant, S.C., shot 7-over 79 at the World Golf Village Slammer & Squire course to lead by two over Joe Slade (84).
Senior Jones Flight (handicap 16.0-19.9)
Larry Dalton, a 67-year-old from Scarsdale, N.Y., shot 20-over 92 Thursday at TPC Sawgrass Valley Course to lead by one stroke over Randy Adcock (92).
Senior Snead Flight (handicap 20.0+)
Clyde Foster, a 54-year-old from Baltimore, Md., shot 17-over 89 at St. John's Golf & Country Club to take a seven-stroke lead over Rod Burns (92).