Pick up "How to rebuild small block mopar engines" on Amazon.com. Read it cover to cover before you start wrenching. It will be $10-15 well spent and give you the basics of what you need and what to do. Ask questions here to fill in the blanks and clear up the stuff you don't understand.
Get the book and lay out all the parts that you'll need so you're deep into the engine rebuild and realize to forgot something or have the wrong part.
Isn't the harmonic balancer off a 318 different than the 340 because one is internally balanced or something?
I think it would be good to make an itemized list of stufff you have so that people can add to that list. Do you have a crank and pistons for the 340 or just the 318?
Check around craigslist.org in your area. A good place to pick up parts cheap locally. I think you can put 360 parts like heads/intake/exhaust on it as it'll make things cheaper.
