1999 GMC Suburban Wont start

I have 99 GMC K1500 Suburban SLE 8 Cyl 5.7L, Vortec. Just recently rebuilt the bottom (new crank and bearings). The vehical ran seconds before the engine was pulled. Engine completed and installed but it will not turn over. New battery, radio, lights, horn all work. I turn the key and no click or anything (leads me to believe there is a missing electrical connection). When I back off the key I hear a small electrical motor (assuming fuel pump). Placed screw driver on starter terminals and the starter cranks the motor strong (engine not seized). Just to be safe had starter tested and in great condition. All harnass's look to be properly connected. Have the spark plugs out to prime the cylinder walls and dist cap off. Tried it with cap on also. No spark plug wires connected at this time. Assuming ignition but not sure where to go from here