A heat exchanger can include a core, a first tank, and a set of guide members. The core can include a first end member, a second end member, and a plurality of tubes that can extend longitudinally between the first and second end members. The first tank can be fixedly coupled to the first end member. The first tank and first end member can define a first chamber that can be in fluid communication with a first port of the first tank and a first end of the tubes. The set of guide members can be coupled to the first end member. The set of guide members can cooperate to define a plurality of first funnels. A narrow end of each first funnel can be open to an individual one of the tubes. A wide end of each first funnel can be open to the first chamber.