Omc 3.0l engine 1987, need help!!!

Just bought a project 1987 Sunbird Corsair and it came with a 3.0l OMC, 4 cyl engine. Took it out, cleaned, inspected, and got it started for about 10 seconds, but It won't start again. I strip the engine of every cable except Ground to block, Pos to starter, +wire to + coil and I use a wire to jump the starter solenoid. It has new coil and points. good spark on all 4 plugs, carburator injecting good fuel, good engine compression, and timing set (#1 spark plug lined with 1 piston TDC on compression stroke). Still can't get it started. Took it to 2 mechanics and they couldn't get it started. I'm out of ideas. I'm a Army mechanic and have rebuilt Ford and Chevy engines before, so I have a bit of experience. Any help will be greatly appreciate. Rod

everything is perfect? good compression, good gas, perfect properly timed spark, but it won't run?
What were your compression numbers?
Define a "good" spark....by good fuel you mean good quantity? or good quality (2013)? or both?

One thing not mentioned is an absence of water in the cylinders... a leaking manifold or riser/gasket could be wetting down the cylinders once the muffs/hose are on.

why all the focus on the wiring? Is/was cranking speed slow? Is a bad gimbal or outdrive (tight gears) loading the engine up? Needs to crank 250 rpm minimum to start.