Trouble brewing

So, I have decided to make the engine my first priority this month.  I was hoping to have an easy time cleaning and re-assembling.  The more I cleaned, the more trouble I found.  The first problem was the heads.  They are not from the same engine.  The numbers show they are from a 1972.  That is not a major problem, as the 72 heads are actually better than the heads from a 60’s model.  I remembered that back in the late 80’s, I broke a valve spring and replaced it.  Upon further inspection, the new valve spring was a little different.  It was actually from a high performance 390.  No problem, I would take it off and put back on an original.  While I was at it, might as well put on all new springs and clean the valves.  After removing the springs and valves, it did not take much cleaning to realize that the valves were different.  I have only removed the right side, but all of the exhaust valves are different.  They are different manufacturers, different lengths, and different bases.  I had the lifters in cleaning solution and was checking them to make sure that the hydraulic lifters operate correctly, when I made the discovery that 4 of the 16 are actually shorter!  So now, I have to replace the valves, push rods, and lifters.  Unfortunately, I am not quite sure what year to search for the parts.  The local parts place list different valves, springs, lifters, and push rods for different years.  I have put information on the ford forum, but the only response I have received are from hard-core 390 rebuilders who recommend the heads be totally reworked to use high performance parts.  I hope that I have a response soon.  Until then, the cleaning continues.
*I have an answer for the heads.  They are from a 1975 F100.  The parts and numbers match.  This came from another forum.  The heads are 360's, but that is standard for the 390's.  I have found all of the parts and this problem should be solved.