I have a 400sbc that I put a 5.7 L05 TBI setup onto.

The injectors are GM5235206 , but they need replaced because they do not flow the same, one drips.

I found out by searching that I have three different choices.

1. Get some 454 injectors. [or copcar injectors]
a. harder to find
b. more expensive

2. Increase fuel pressure, and keep same size injectors
a. still have to buy injectors but sounds too easy to be
true.

3. Get a 454 TBI and use the 350 injectors
a.better airflow without doing all the ultimate TBI mods
b.more options for future improvements.

Ideas change over time, and the bigger injector is the oldest one.
The higher pressure is a newer idea, but reviews seem mixed,
and of course I am aware that all these mods will REQUIRE chip burning.

The last one comes to mind because I found a 454 TBI at the junkyard with the injectors missng. And I seen this option mentioned on the www.binderbulletin.org
Since this is a stock motor, and not high reving, I may not need the bigger injectors, but if I make improvements later, all I'll need to add are the bigger injectors.

So what is the current opinion on how to fuel a 400 or 406?

Thanks
Bob

 

80 lbs injectors at 18 lbs FP at 90% duty cycle will support 320 HP.
oh yea. you will need a higher flow fuel pump

 

I would think about the 454 tbi with 80 lbs injectors as well as a new fuel pump and an adjustable fuel regulator. Save's you time and money in the long run, for more perfomance. I have herd however that the 454 tbi unit can be a pain the #@$ to set up correctly. Im sure that you will get some more ideas soon, Just my thoughts