A process for upgrading feedstocks containing not less than about 200 ppm metals, an API gravity of less than about 20.degree., a Conradson Carbon of more than about 8%, by hydroconversion with hydrogen in the presence of a naturally occurring inorganic material as a catalyst. The invention further provides, inter alia, subsequently fractionating the hydroconverted product and solvent deasphalting the distillation bottoms and optionally hydrodesulfurizing atmospheric distillates and the mix of vacuum gas oils and deasphalted oils separately. When a heavy crude of 12.degree. API, 10% Conradson Carbon, 3.2% sulfur and 350 ppm metals is fed to this process, more than 90% (v/v) of a synthetic crude of 25.degree.API, 0.17% sulfur and only 13.8% (v/v) 950.degree. F.+ fraction may be obtained.