I just bought a used 2001 that has a FASS system and a thoroughbred diesel high output VP44 on it. I wanted to switch those over to my current truck. How much work will it take to do this and put the new one back to stock? I haven't installed either of these pumps so I want to be sure it's not a huge project i'll be undertaking.

 

Taking the FASS off and installing to yours, not a big deal. Putting the one you took it off back to stock, you'll need some fuel line probably but easy. I'd say about 4hrs. Replacing an injector pump, usually about 4-6 hours the 1st time someone does them. Do a search on here, there is a video series how to do the work.