Good god.... if that sad engine left you feeling that the 3500lbs slab it was dragging around was fast... you might want to reconsider the rebuild and just swap in a nice rebuilt 4 cylinder from a Celica or something... I don't know if you'll be able to cope with much more.
No sounds... could be because it had finally finished coughing up chunks of lung and moved on the whole dying quietly stage. That thing was hurting... I'll be amazed if a complete rebuild isn't required (including boring the cylinders and polishing the crank).
You already got the quote? $565 for what?