Improved catalysts for the selective conversion of straightchain hydrocarbons contained in a hydrocarbon feed comprise a synthetic, relatively small pore size crystalline aluminosilicate zeolite. Preferably, the synthetic small pore size zeolite is combined with a metallic hydrogenation component and used in the selective conversion of low octane-producing normal paraffins to upgrade the hydrocarbon feed stock. The process is preferably conducted in the presence of added hydrogen at elevated temperatures and pressures.