determining injector size
 

How does one go about determing the initial injector size for an ls3 headed lq4 with a 408 stroker kit.also has a gmpp 4150 intake on it also.

how much power you plan on making or think it will make. I'm going to estimate 500-600, and naturally aspirated.

The stock ls3 engine uses 41.74# @ 58psi injectors...so there is base to go off of.

I would recommend some 42# @ 43.5psi (48# @58psi) injectors or larger. No more than 60#

Either dual 255 pumps or a 255 and an external such as a bosch 044 or something.

I was estimating 550 or so and yes naturally aspirated. I was looking for 60# injectors but was unsure if that was the correct size. Thanks for the info I appreciate it.

contact Fuel Injector Connection and grab a set of their 546cc (52# @ 43.5psi) injectors and you will be set.

Fuel Injector Connection, also has a calculator on its website.

I'll also say my friends car (LS1) with AFR heads, cam, etc. All bolt ons you can possibly do, made 480hp and 440tq and runs 36# @43.5psi injectors (actually 41.57# @ 58psi, our fuel pressure) and only had a duty cycle of around 6x%.

So I would believe around 60# would be the largest you would want to run.