That sucks !!! sorry man. ok what kind of motor are we dealing with?

So nothing on #7 did you hear anything when it dropped
Did it run with only 7 cyl.
My guess dropped a valve, it bent and thats that! Now i have seen a valve break like a cresent moon and was able to fix it .
pull the plug out of that cyl , remove the rocker arms and check the hieght of the valves if they look good , your half way there!
next find something to pry with and push down a little on the valves (one at a time!!! ) wont have to move them very much, to know if its bent!
if you want i can walk you thur it!
Call me! 408 671 8449
Good luck. Tony.