Forrest G. (Spec) Towns, who parlayed a barefoot backyard high jump into a world-record career as a hurdler and then spent 34 years coaching championship track teams at the University of Georgia, died on Tuesday at the Athens Regional Medical Center in Georgia.

His family said he had died of a heart attack.

He was 77 years old and had lived in Athens since going to the university in 1933 as an over-aged freshman on an improbable athletic scholarship. Set Record in Hurdles

Mr. Towns won more than 60 consecutive hurdling events. He broke the world record in the 110-meter hurdles and than lowered his mark twice. He won a gold medal and set an Olympic record in the event at the 1936 Games, and two weeks later became the first man to break 14 seconds in the race. And then, having demonstrated his supremacy over every competitor with two legs, he capped his career by beating a horse to the tape in a 120-yard hurdles race in 1937.

He retired from competition in 1938 to become an assistant track coach at Georgia, then took over as head coach in 1942. Over the next 34 years his teams won 21 Southeastern Conference outdoor championships and 5 indoor titles.

Last year the university's track was named in his honor, and yesterday the Georgia athletic director, Vince Dooley, described him as a Georgia legend. Never Ran in High School

It was a legend that almost never happened.

Mr. Towns, who got his nickname from his profusion of freckles, was born in Fitzgerald, Ga., and later moved to Augusta. Although Mr. Towns, who was 6 feet 3 inches tall, had clear ability as a youth, he never ran track for his high school team. His family was too poor to buy the track shoes team members were required to supply for themselves.

The turning point came a couple of years after he graduated from high school. A neighbor saw him in his back yard, barefoot and in overalls, jumping over a broomstick held by his father and brother at what the neighbor reckoned was world-record height. The neighbor told a local sports columnist about the scene, the columnist opined in print that the Georgia track coach, Weems Baskin, might be missing a pretty good bet, and Baskin took the bet.

Although he won his scholarship as a high jumper, it was as a hurdler that Mr. Towns made his mark. As his son Preston told it yesterday, "When Baskin saw how long Dad was cut in the inseam, he asked him to try the hurdles and Dad said he didn't know what hurdles were but he'd do it."

In addition to his son Preston, Mr. Towns is survived by his wife, Martha; a sister, Evelyn Eskind of Vero Beach, Fla.; another son, Robert F., and eight grandchildren

Forrest Towns (1914)