'89 22re won't start

I have an '89 22RE that I am having a killer time getting started. When I turn the key I either get a single hard clunk, or the engine will slowly turn but not fire up (this happens both by clutch starting and clutch cancel switch). I have replaced the battery, both cables, starter, ignition switch, checked the engine bay wiring harness, checked the timing, ohm resistance in the coil and wires, and pulled out a lot of my hair. Does ANYONE have any idea what else this could be short of now ripping out my interior wiring? I would love to avoid redoing my interior...........