Hydrocarbon conversion processes and catalysts used therein

A process for converting hydrocarbonaceous oils and polynaphthenic components into products of lower average molecular weight and lower average boiling point comprising contacting said hydrocarbonaceous oils and polynaphthenic components under hydrocracking conditions with a catalyst comprising an ultra stable Y zeolite base, wherein said Y zeolite has a unit cell size greater than about 24.55.ANG. and a crystal size less than about 2.8 microns, an amorphous cracking component, a binder, and a catalytic amount of hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal, and mixtures thereof.