2004 Toyota Sequioa Limited

2004 Toyota sequioa v8 driving down the highway it just quit on me.  Had it
towed to nearest garage to diagnosed. Was told fuel pump fine filter ok but no
compression on 4 cylinders on one side.  Was told most likely engine shot.
Would cost 10,000 for rebuilt engine. I paid $135.00 for diagnosis had it towed
home.  I was thinking if it was a timing belt issue and it did indeed cause the
valves to collide with the pistons there should be damage to top of pistons. I
borrowed an inspection bore scope and found out there is no damage to
valves or pistons. What should my next step be? It has about 200,000 miles on
it. Please HELP!! Thanks