I feel your pain.
I used to own a p71 crown vic. Flexplate decided to break on me shortly after purchase.
Drop the trans, replace flexplate, get tranny fully tightened back on.... then realize I forgot the stupid metal spacer plate that fits between motor&trans. AAGHH.
Remove tranny, fit spacer plate, fully tighten trans to motor again, start putting nuts on the converter studs and notice that the converter studs are scraping on one section of the spacer plate WTF! I bent the spacer plate during the first disassembly by using a pry bar to pop the trans off the motor, it was really stuck.
Drop tranny AGAIN, buy replacement plate, install, and all was well.