This summer 24 young men from Highland, Utah, will travel to a remote island on Lake Titicaca in Peru to help build a school . . . out of stone . . . by hand.

For eight days in June, the boys, members of Explorer Post 805, will chisel, hammer and saw chunni blocks that will then be used to form a three-room schoolhouse adjoining another building in the primitive village of Taquile.During their stay in Taquile, the Explorers will learn firsthand what it is like to be a Peruvian Indian: They will live in the villagers' homes - rough-hewn stone huts with dirt floors and straw beds - and they will eat what the villagers eat - mutton, vegetables, fish and guinea pig.

"When they feed us the guinea pig, we'll smile and like it. We've been told they burn the hair off," said Lynn Scoresby, adviser for the post.

Modern Western conveniences and pleasures will be checked at the U.S. border; instead, these boys will have the opportunity of a lifetime to see how others live. More importantly, they will have an opportunity to learn what it takes to make a difference in the lives of other people.

The boys are traveling to Peru as part of an expedition formed by the Center for Humanitarian Outreach and Inter-Cultural Exchange (CHOICE), a non-profit agency that organizes, guides and directs humanitarian and development efforts in poor countries. CHOICE was founded by Tim Evans, a Salt Lake dentist, as a means of providing organized and skilled volunteer manpower on short-term charitable projects in under-developed countries.

Evans is also the founder of the Andean Children's Foundation, an international development agency that concentrates on projects in the Andean region, particularly Bolivia. Difficulties in coordinating volunteer efforts in Children's Foundation projects led Evans to form CHOICE.

Volunteers who participate in CHOICE projects donate their time and pay their own way to and from project sites.

This is the first time Evans has allowed a group of boys to participate in a CHOICE project, although a precedent was set by a 13-year-old boy who participated in one of the first CHOICE projects to fulfill an Eagle Scout project.

Although Evans has never had a large contingent of young people on previous CHOICE projects, he is "excited to see what will happen." Scoresby is equally excited about the growth opportunities the trip to Peru will provide the Explorers.

"We've got to take challenges and face them," Scoresby said. "That's how you help men grow. Basketball can only help so much. Then you've got to go to Peru."

Already, the boys are involved in extensive preparations for their trip: Two are preparing cultural education classes on Peruvian culture and history; another is in charge of seeing that all the necessary paperwork - passports, liability releases, physical examinations, etc. - is turned in and in order; another is preparing to act as a tour guide; one is securing materials (hammers, chisels, saws and goggles) the boys will take with them and use to build the school. Several Explorers are heading a fund-raising effort to help cover the group's travel expenses and to buy materials to stock the school they'll build - slates, chalk, pens, pencils, note pads, crayons, etc.

Still ahead of the boys are cardiovascular workouts to prepare them for the altitude; at an elevation of 12,507 feet, Lake Titicaca is one of the highest lakes in the world. And, a series of vaccinations will be necessary to protect the youth from such diseases as yellow fever. Shots and workouts aside, the boys are, understandably, excited.

"We get to be ambassadors from our country going down there to see what other countries are like," said Eric Frandsen.

As part of a cultural exchange, the "ambassadors" will be bearing gifts - artificial cloth flowers for the women, fishhooks for the men, and balls, yo-yos and cloth dolls for the village children.

Evans, who is leading the expedition, said the villagers, too, will assume the role of ambassadors.

"They will give us a fiesta in order to liquidate their account," Evans said. "When we leave they'll have a big sheebang and come out in costumes, and spend more than they should (on the fiesta); there will be dances and speeches and lots of food."

By the time of the fiesta there also will be 24 Explorers and 500 Peruvian villagers who know a lot more about each other's worlds.