IIRC, the bomb was supposed to be planted in the library at Columbia University according to (then NYC Chief of Detectives) Al Seedman’s biography, “Chief.” They were trying to distill the dynamite and concentrate it when it exploded.
Everything I’ve read says that the target in 1970 was Ft. Dix. However, they were playing with 100 lbs. of dynamite, so they may have had multiple targets.