What if I dont have a breaker bar? >.>Well, not the cam itself, but the eccentric mounted to the front of it. Look at the pic below, & see the offset circle in the center of the top sprocket. If you rotate the engine so that offset is up, then the pump installs easier. The lever from the pump rides on the bottom of that offset.
You can rotate the engine with a breaker bar on the big bolt inside the bottom pulley. Make sure the key is off, & disconnect the coil wire to keep it from trying to start while you turn it. Brake set, Trans in neutral or park. Be aware that one full turn of the bottom pulley & sprocket (Crankshaft) is only one half turn of the top sprocket & eccentric (Camshaft). It'll be hard to see the eccentric thru the opening, but you should be able to tell by trying the pump until it fits.