A flow-through assembly, comprising a rotating variable choke assembly for varying a flow rate of drilling fluid passing therethrough, the rotating variable choke assembly comprising: a rotary component, comprising: a rotary component body having at least one port extending therethrough, and a rotary component central bore permitting fluid flow through the rotary component body, the central bore permitting fluid flow through the entire length of the rotary component body; and a tapered surface; and a stationary component, comprising: a stationary component body having at least one cooperating port therethrough, and a stationary component central bore permitting fluid flow through the stationary component body; and a complementary tapered surface for engaging the tapered surface of the rotary component when the rotary component sits in the stationary component, wherein the rotary component and the stationary component are configured for use in a string for downhole operations, wherein the complementary tapered surface resists transverse travel of the rotary component such that the rotary component central bore and the stationary component central bore remain substantially aligned while each of the at least one port of the rotary component enters into and out of alignment with one or more of the at least one cooperating port of the stationary component when the rotary component is rotated relative to the stationary component by a selectively activatable motor. a rotary component, comprising: a rotary component body having at least one port extending therethrough, and a rotary component central bore permitting fluid flow through the rotary component body, the central bore permitting fluid flow through the entire length of the rotary component body; and a tapered surface; and a rotary component body having at least one port extending therethrough, and a rotary component central bore permitting fluid flow through the rotary component body, the central bore permitting fluid flow through the entire length of the rotary component body; and a tapered surface; and a stationary component, comprising: a stationary component body having at least one cooperating port therethrough, and a stationary component central bore permitting fluid flow through the stationary component body; and a complementary tapered surface for engaging the tapered surface of the rotary component when the rotary component sits in the stationary component, wherein the rotary component and the stationary component are configured for use in a string for downhole operations, wherein the complementary tapered surface resists transverse travel of the rotary component such that the rotary component central bore and the stationary component central bore remain substantially aligned while each of the at least one port of the rotary component enters into and out of alignment with one or more of the at least one cooperating port of the stationary component when the rotary component is rotated relative to the stationary component by a selectively activatable motor. a stationary component body having at least one cooperating port therethrough, and a stationary component central bore permitting fluid flow through the stationary component body; and a complementary tapered surface for engaging the tapered surface of the rotary component when the rotary component sits in the stationary component, wherein the rotary component and the stationary component are configured for use in a string for downhole operations, wherein the complementary tapered surface resists transverse travel of the rotary component such that the rotary component central bore and the stationary component central bore remain substantially aligned while each of the at least one port of the rotary component enters into and out of alignment with one or more of the at least one cooperating port of the stationary component when the rotary component is rotated relative to the stationary component by a selectively activatable motor.