The ATP B3Z-HD Clockwise, Rope Seal type Pump is a 4 x 3 Centrifugal Frame Mounted Water Pump. This Heavy-Duty pump has a 1 1 / 2 Shaft with a 3 / 8 Keyway, and a KEYED Impeller with 1 1 / 4 Bore, making it stronger than the standard B3Z. This pump is THREADED on both the suction and discharge side and at 2500 RPM, performs at a rate up to 800 GPM at 70 PSI. When driven directly via PTO, this pump is used for trucks with Automatic Transmissions. This ATP Water Pump is a direct replacement for Berkeley Pump B3ZRM (B86070).