Choice of injector

How can we determine the best injector to use, so that you can grow with the same injector and not having to buy a whole new set when going from NA to Forced induction on E85 fuel. Expecting 550 crank Hp for the run in of the engine. Then later fit engine with a Centrifugal supercharger to expect 650 Crank hp (700hp tops)

LS1, 269cam. Forged internals with compcam valve train (stock specs for piston and train. 6.125 con-rods) MSD Atomic Airforce intake manifold.

FAST LS3 fuelrails,

The injector sizing calculation in the course is all you need. I'd just suggest using the power target you ultimately have in mind and put that into the equation. If you're planning on running E85 then you're going to need to multiply the pump gas values that the calculator produces by about 1.35. Some times the required injector size for E85 can mean that idle quality on pump gas may be compromised but with the modern crop of performance injectors this only becomes an issue when you're making pretty serious power.

Running the numbers for 700 hp you're probably going to need to be around 51 lb/hr on pump gas or about 70 lb/hr for E85. You'd have no trouble running a 70 lb/hr injector on that engine on pump gas so you should be golden.

Thanks. Also taking into account of upgrading to forced induction at a later stage ?

Would want breathing room for that (70lb) injector to handle 700hp while operating in its happy place between upgrades.

Brings me to another question. Is it safe to turn the engine on after installing the upgraded injectors and what precautions should be

taken into account before and after installation (mostly ecu/computer wise)