360 wont start.........

i had my 360 running for a week now and it ran great very good oil pressure and it stayed around 180-190 degrees....sounded awesome with great throttle response....yesterday went out to the barn to fire it up and i got one loud click when i turned the key.....ok i replaced the starter selonoid on the fender....hooked it all up one loud click....next step replaced the starter....once again one loud click...puller the starter off hooked it to a battery grounded it worked fine.....motor turns over with the water pump fan and some strength....checked all cables running from battery to noid..to starter all have good crimps and solid connections.....thought maybe becuase we dropped the rear crossmember that the tranny had shifted when we put it back up making it be in a bind and the starter wont turn the motor....messed around with that put the tranny and crossmember in the exact same bolt holes in the same spot as before.......battery reads 13 amps on the volt gauge......me and my buddy are at a loss....we have no idea why it makes one loud click....i even put my hand on the flywheel and starter when he turned the key and could not feel the starter hitting the fly wheel.....if some one can help me with my mess that would be awesome i need suggestions.......