First Diesel, Lots of Questions

[crash-harris]

So from everything that I've read, it seems like my longer start times could be from worn injectors. I'm assuming this since I installed the new ZD9 GP's when the truck had been sitting for 2 days and it started after 3 cranks. Times are a little longer again. Could still be air intrusion though. Now that some other things are taken care of, I'm looking at getting new BB code injectors when I can.

The question is, I've read that you should REPLACE the IP with new injectors. Could I just get the current IP retimed? Could I do it myself and how?

Would also be doing a return line kit with new injectors of course.

Checked for timing marks on the IP to advance it just a tad. Looks like someone already has. The mark on the pump is about a dime width toward the passenger side from the mark on the engine.