Having done this (1 truck from 2), including a body swap. I'll throw in my 2c here.
Go through both trucks, and decide (at least for major assemblies) what is going to be used from which truck
Plan ahead. Don't strip axles out before you're ready to replace them, as working on 2 trucks takes a lot of space, and being able to move them helps a LOT
If you're moving bodies or front end sheetmetal around, try and do as much mechanical work with the body and sheetmetal off as possible. it's a LOT easier, and a LOT faster.
Similarly, if you're going to be doing any modifications, do them when you have access
Be prepared to walk away and do something else. May be for 10 minutes, may be for a week. That said, also be prepared to work into the wee hours of the morning for days and days in a row. When you get a good groove going, take advantage of it.
Don't give up. It WILL get finished. try and space out major accomplishments, as each one is a huge boost in drive to keep working.
Don't put off getting it to run until its ready to drive, then you only have one accomplishment. if you get it to start, then you'll find you have new energy to work towards getting it driving.
When it comes down to it, its all about a little bit for foresight and planning, and a LOT of plain old work ethic.
