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Message: [QUOTE="CurtisF, post: 1061311, member: 829"] It doesn't matter what injector. You can run 400/400's on PMR's. Never mind the max hp that an injector is capable of. Everyone just get that out of your collective heads and throw it out the window when it comes to PMR tuning. The idea of "this particular injector is capable of X amount of horsepower". Toss it away. What matters is how much fuel at what time and duration. That will be mainly up to your tuner, and partly what you want him to do. The injectors you choose will determine what your tuner has to work with. After that it's supporting mods being able to make the power time and time again with good performance and manageable EGT's. First, stop looking at horsepower. Look at torque and set a limit. For PMR's, make it under 900 lb/ft if you want it to live as long as possible. Go higher and good luck, you're going to need it. Why torque? Because that's your best indication of cylinder pressure without having an actual tool to measure the cylinder pressure in real time. High cylinder pressure is what is going to pop a rod, and PMR's just love to jump out of the block when cylinder pressures spike. You can have 400 hp and 1200 lb/ft of torque, or you can have 500 hp and 900 lb/ft of torque. Which one has the higher cylinder pressure? I bet you can guess at this point. As for the injectors, larger nozzles will give you more horsepower with less torque, because they have a smaller injection window that they can work with and you can continue to make good power at higher RPM's while keeping EGT's nice and low. But at the same time they are harder to tune for many, and require some refinements to achieve a nice daily driver that you are truly happy with. On the flip side smaller nozzles are easier to work with in regards to making your truck a pleasant daily driver, but require a much longer injection event duration. This longer injection event can increase EGT's and limits your upper RPM power as that injection window shrinks. Pick a tuner you are comfortable with and talk to him about your goals and what components you plan to toss under the hood. The two of you will be working close together until that truck is running as you want it, so both of you better be speaking the same language before you open your wallet. Is this going to push the limits of the PMR's. Uhhhhhhhhh, yeah. Of course. You're going to gamble, just know that here and now. Understand what can possibly happen, prepare yourself for it, and don't be surprised if it happens. For my own truck I've been very happy with it. The thing is a work beast and nothing out tows it up a mountain pass. Period. It's been alive in it's current configuration and power level for several years and tons of miles, and it hasn't skipped a beat. Knock on wood it keeps this up for many many years to come. *Your experience may differ. [/QUOTE]