My stock injectors are 42psi the motor is stock 5.3 Headers 2.5 exhaust no cat's 112 Maggie . Looks like mine are doing some misfiring so stay stock or go bigger for more power. Truck runs great but you know how it goes more power is always more fun.

 

if these are stock injectors they are 28lbrs, 38lbrs for flex fuel. the 42s or the 8.1 injectors.

 

Mostly depends on your build, and your goals. If you are not maxing out your 42 lb injectors, going bigger will not give you any more power.

Just to give you an idea, with my current setup, I shift at 6400 rpm and the injectors are at 102% duty cycle. I'm not sure how stock your setup is, or isn't, so I really don't have any way to recommend 42's or 60's. Do you have any way to datalog your IDC?

If you just have dirty/clogged injectors, a Motorvac fuel system service should correct the problem, and save you money.

 

I agree with this.My injectors are at 95% with 3.0 pulley.

 

Thanks a lot guys. Running Lucas Injector Cleaner in the take now. Hope that will clean it out. Truck ran fine going to Louisville put gas in it there and has run like crap every since.