10" Converter in a stock 904

That's up to you. It's nothing special and it's possible the converter that's leaking, although not as likely as a pump seal. You can buy stock replacement converters from www.bulkpart.com for lsss than $100. And to tell you the truth what your doing sounds kinda risky to me, putting a 37 yr. old used trans. in a car with a hot engine, low gears and possibly a high stall converter is generally asking for trouble unless you know for sure it has been properly rebuilt sometime recently.

Also in case you don't know this the 360 takes a weighted converter that's different from a 318 because 360's are externally balanced engines where-as 318's are internally balanced. You need to either get a converter with a balance weight on it for a LA 360 (not the same as a magnum 360) or install a B&M or TCI flexplate that's designed to balance the engine so you can use a non weighted converter.