A process for producing a product slate, which includes at least three base oil grades having kinematic viscosities at 100.degree. C. within the range between about 1.8 cSt and 30 cSt, from a waxy feed having an initial boiling point of about 340.degree. C. or less and a final boiling point of about 560.degree. C. or higher, said process comprising (a) isomerizing at least a portion of the waxy feed, whereby the amount of isoparaffins present are increased; (b) distilling a first portion of the isomerized waxy feed in light block mode operation into at least three base oil fractions having different boiling ranges; (c) distilling a second portion of the isomerized waxy feed in medium block mode operation into at least three base oil fractions having different boiling ranges; and (d) blending at least one base oil fraction produced from light block mode with at least one base oil fraction produced from medium block mode to produce a lubricating base oil blend meeting a target value for at least one pre-selected property.