I would honestly just hand your car over to a reputable shop, let them use their contacts to find an engine and do the rebuild. There is no reason why you should be looking for the block at this point in time because there might be more things wrong with your car (no offense) taking infact you wouldn't even correct a "major oil leak."
A&L in Palatine
Boyce Bodywerks in Naperville or Batavia
perhaps VS Motorsports can direct you in the right direction
Stop looking up engines and do this the right way. You already screwed up a nice car with your negligence on the oil leak. I'm done with this thread.