Truck Shop
Senior Member
IIRC the stock injector was 8 orifice with .007 orifice, the 10 orifice was .0085 and IIRC the plunger and barrels were direct feed/high flow.
How old are you? A good way not to look like an a$$ on the first few posts is to enter mild,Hey fellows not to get into anyone’s business…you do NOT need rail pressure over 195 pounds. The way to set your engine is to have the pump set with the stiff torque spring (red stripe) and go lower on the button size for fuel pressure but not over 195 pounds of rail pressure. Have the injectors flow rated so they can handle the new amount of fuel you are sending them now. If you do not have them flowed rated you place too much pressure on the cam and wear the lobes on the cam because injectors can’t handle the amount of flow. These Cummins injectors push fuel by the cam lobe moving injectors up and down
Set your 400 big cam III at 20 % above specs and match injectors to pump you will not hurt the engine and she will tote the mail. One last thing set aneroid valve enough to give it better throttle response….but not so much she smokes bad. You just a little dark lingering puff when changing gears. Then get in her and start “stepping”