I recently had to replace my VP-44 and got my replacement from Bluechip. I spent the money for the best upgraded pump since I plan on keeping this truck for a long time. Was cheaper to fix the truck than buy a newer one.
Use the Bluechip diagnostics section to determine if it is truly the VP-44 or the Apps. When my truck first started acting up, a few years ago, I used the diagnostics to determine it was the Apps, which I replaced with a Timbo apps from Geno's Garage.
I finished putting in the VP-44 today and drove my truck to work. Been stuck driving my commuter car and it was fun to drive my "Old" truck again.
Good Luck and let me know if you need any tips etc..about how I went about replacing my VP-44.