Rear Derailer replacement
OK, I've searched through and can't find the answer I need although I can't imaging the question hasn't been asked, probably just bad searching.
I have to replace the rear derailer on my 1982 Schwinn World Sport. The original was a suntour honor. Disraeli Gears lists it as 57 mm center to center max cog 30 total cap 28 top normal logic. Gearing is 40/52 chainrings 14/28 freewheel (5spd).
My question is how much of that stuff is important. Looks like pretty standard gearing. Does that mean pretty much any rear derailer will work or do I need to worry about staying close to the original specs?
See several "nice" used rear derailers on ebay but have no clue as to weather they'll fit cause I can't find the specs on the newer but still not current models. Also got seveal responces locally on a craigslist WTB but once again don't know enough about selection. Found plenty of stuff that I think I could replace it myself if I knew what to get.