Jim, I am running the 904. I just need to adjust the kickdown. Everyone that is smarter than me pretty much says it will live just fine behind a mild 360. It is also lighter and less rotating mass. We'll see. The good news for me is I have an extra if it does go. If you are doing this, do yourself a favor and put the headers in BEFORE the engine. I didn't and am having a great(not) time with the driver's side. I am sure I will be happy with the 360 as I would bet I didn't have 150hp in the 318. Low compression, stock cam etc. What a pig.
Jason