The 240 has a mechanical fuel pump on the engine. So there is no direct replacement. The walbro is your best bet. It is an external, in-line pump. You didn't mention if you are going to use the stock tach and speedo or go with after market. It is possible to use the stock speedo by using the CableX box, and to have John's set up your tach. Also, if you didn't get a drive shaft from JCI, you'll need to have one built. While the engine, tranny is out would be a good time to replace the clutch, especially if your donor has a few miles on it. Good luck and keep us posted.
Mike