I was just given a 69 deville conv. with a fair body ( nothing major) with the 472 engine. The engine is stuck, and when I changed the oil about 4 qts of water came out with it. I want to put an engine in it but need to know what will bolt right in( will all the big blocks bolt up)? Also, if anyone is in the phila area selling a used motor please let me know.

This is a very easy swap. Any year 472 RWD or FWD will swap in. Same for 500 425 and a 368 with a carb (fuel injected version would be too much work). You might have to change your oil pan and pickup depending on what car the donor engine comes from. Some oil pump housings are different also so save yours if it looks OK inside or order a new pump.
You can probably find someone interested in the cylinder heads from your drowned 472 after you get it out.