An installation for moulding of three dimensional products from a mass of pumpable foodstuff material, for example from ground meat. The installation comprises a feed pump and a moulding device with a mobile mould member having multiple mould cavities. A mass feed member is arranged at a fill position relative to the path of the mobile mould member, which mass feed member is connected to an outlet of the feed pump. The member has a housing defining an elongated chamber with a longitudinal axis and having a pair of spaced apart long lateral walls, short end walls, and a bottom wall facing the mould member at the fill position along the path of the mould member. The bottom wall is provided with a discharge mouth formed by one or more discharge openings spanning the path of said mould cavities, so that foodstuff mass flows into each row of mould cavities via said discharge mouth. The mass feed member is provided with a single elongated plunger that is slidably received in the chamber, sliding between the lateral walls and the end walls. At least one lateral wall is provided with an introduction mouth formed by one or more introduction openings spanning a major portion of the length of said lateral wall.