new starter, new battery. experimented with different numbers of shims. just replaced intake manifold had to remove distributor but im fairly confident the timing is close. when i turn the key the starter tries to turn the engine over but acts like its not powerful enough to do so

 

Over advanced timing can cause a slow cranking symptom. Try pulling the coil wire or power to the distributor then crank it over if it cranks faster, back off the timing.