at what horsepower is a piston lift pump really needed, also where can you buy one and what is the price range?thanks

 

Let me try:
400 HP
$200
Any Cummins distributor

 

Go to the tech articles. scan down toward the bottom. There is a section on the piston lift pump. It has part numbers and everything you need.
If you have put bigger nozzles in and start turning your fuel screw in, I would say its time for the piston pump.
Good luck.

 

If you've changed injectors the piston lift pump is a good idea. You won't get 400 HP without one (or an electric pump of similar capacity). Other than that Begle1 got it right.

 

The 400 was an estimate...

How much can you get with the stocker?

 

I made 302 with the stocker.

 

I made 332 HP with a stocker, I guess the question is, At that HP how long will the injection pump last. The issue is, Our little injection pumps rely on fuel to keep it cool. You may make 400 HP with a stock lift pump but how long will it last. We want power as well as reliablity.
If you can afford $200 go for the upgrade and you will have no worrries about the fuel system.