If your OCD and take your time the first time through a job I'm betting you want to budget a whole weekend for this. I haven't done anything on my engine yet but I know it took me 8 hours to do my first axle seal job on the rear because I took my sweet time and quadruple checked everything. A big chunk of that granted was getting those damn drums back together...drum brakes suck to work on. Second side was about half of that because I felt more comfortable with the job. Also I would say heed Tim's advice and have the "while you're in there" mentality. The fewer times you have to take these old trucks apart the better and if you don't know the condition of other components that you can easily replace while you are there then why not take care of it.