Got some replacement head bolts, but I noticed that they are 12 mm instead of the old 14 mm that were originally on there. Threads are the same size, so it shouldn't matter. However, the old ones had washers, the new ones did not come with the washers. Should I re-use the old washers??? The bolts are exactly the same height, as are the threads.

 

Yes, use the washers. Oil the bolts and clean out the threads with a tap or at a min a wire gun bore brush. Follow the torque procedures. enjoy