Block: 4023102 Head: 4021854 Engine Good Running ALLIS CHALMERS 2800 NAT 6 Cyl Diesel Block: 4023102 Head: 4021854 Test Ran: 10- 16-13, Base Engine Runs Good, Injection Pumpwont Advance, Can Rebuild This Injection Pump Or Use Your Old One, 30 Psi Oil Pressure, Restarts Good. Rotary Pump Additional Core Charge Of $ 750 Required