A fluid end assembly of a hydraulic fluid pump includes a housing having a first housing bore and a second housing bore offset axially from the first housing bore. A plate is fastened to the housing. The plate has a first plate bore axially aligned with the first housing bore and a second plate bore axially aligned with the second housing bore. A first removable valve cover closes the first housing bore and a second removable valve cover closes the second housing bore. A first retainer engages the first plate bore and abuts the first removable valve cover and a second retainer engages the second plate bore and abuts the second removable valve cover.