Hercules Running Rebels and the Top Pacers Invitational Preview   San Pablo, CA.- The Pacific Association will travel across the bay this weekend to San Pablo, California to compete in The Hercules Running Rebels and the Top Pacers Track Club Invitational. The meet will take place Sat-Sun May 21-22 at Contra Costa College Stadium.   The meet begins Saturday morning at 8:00 a.m. with field events. The Track events start at 9:00am with the Midget Girls 4x800 Relay, continuing thru to the Open Mens 800. Then there will be a Parent Appreciation Ceremony to honor Parent and Guardians before competition resumes with the 110m Hurdles.   The Hercules Running Rebels and the Top Pacers Track Club Invitational has traditionally produced several standout performances. The top sections of the 4x800, 100 meters, Hurdles, 800 meters and the 3,000 meters are all slated for Saturday. All together 28 events will be contested involving post-high school and high school runners. The top eight men and women from Saturday's preliminaries will advance to the finals.   The meet will continue on Sunday with the Sub-Bantam Girls 4x100m Relay, Race walk, 200 meter finals, 1500 meters, 200 Hurdles, 100 meter finals and finally the 4x400 Relay.   Competing at the Invitational will be a mixture of Pacific Association and regional programs with such teams as Phoenix Gliders, Cougar Speed, Team Onalysis, Revolution Express and the Sacramento Speed just to name a few   The Hercules Running Rebels and the Top Pacers Track Club Invitational begins at 8:00 a.m. on Saturday, May 21 and is free to the public. Parking outside the track will also be free and available on a first come first serve basis.