TOLEDO, Ohio (AP) _ Some graduating seniors are threatening a protest over the selection of a younger classmate as the 1987 class valedictorian.

Howard Rhodes Jr., 16, the son of two high school dropouts, will graduate in June, only three years after entering Waite High School.

He has completed all the requirements, posting a 4.2 grade-point average on a 4-point scale. The better-than-perfect score resulted from extra points awarded for honors courses.

School officials initially designated 17-year-old Jean McLaughlin, a four- year senior, as valedictorian. But Rhodes pointed out last month that he had enough credits to graduate and had the highest grade average.

Rhodes, who had been listed by the school as a junior, officially was elevated to the senior class and named valedictorian.

Miss McLaughlin, who has a 3.9 grade point average, said it was disappointing to have the honor go to a student who did not begin high school with the other class members.

The dispute stemmed from confusion over whether Rhodes' grades should have been considered when seniors' grade point averages were ranked, Robert Roman, executive director of secondary education for the Toledo school district, said Wednesday.

The confusion, Roman said, was caused by a change in graduation requirements five years ago that qualified any student with enough credits to graduate as eligible for graduation honors and awards.

Before then, the valedictorian was the senior, but not necessarily the graduate, who earned the highest grade point average through seven semesters.

''There's no question about this young man. He is a valid candidate and will not be denied being the valedictorian,'' Roman said.

Principal Steve Contos said he would meet with class officers and student leaders in an attempt to head off any protests over the choice of a valedictorian.

Some students had said they were considering a protest, including disrupting Rhodes' speech.

Rhodes said he planned to start classes at the University of Toledo this summer and become a math teacher.

''I want to get on with my career. I see it as a waste of time to spend a whole other year here,'' Rhodes told The Blade of Toledo. He was in class and not available for comment Wednesday.

Rhodes is the oldest of five children of Howard and Judith Rhodes, who dropped out of high school to marry, Mrs. Rhodes said. Mrs. Rhodes is a homemaker, and her husband works in a flour mill.

''They wanted him to walk down the aisle (at graduation) and keep his mouth shut,'' Mrs. Rhodes said. ''They razz him all the time, saying he didn't belong to nobody's class. They said he was a problem because they had a junior graduate before, but never one that was the top one.''