I would talk to a local dyno tune shop before upgrading injectors. Especially if you are getting headers because they will heat up and start melting things, add more fuel and you will melt stuff. You have already deleted your cats so it is probably running rich already. The LT4 only had 26 or 28# injectors and it made 330 horsepower. But the vetts did not have your steel flywheel which boosts your torque.

 

it has been dyno tuned which means it is dialed in on fuel and air and in order to delete the cats you have to turn off the post 02 sensors, its not running rich! thank you

 

headers and injectors have NOTHING to do with each other. pretty sure the LT4 had 24 pound injectors just like the LT1 did.

and you're not talking the same horsepower that we are. you're talking flywheel horsepower is 330 on an LT4...when we give horsepower marks, we're basing it on REAR WHEEL horsepower...therefore our 330RWHP is a lot more than your 330FWHP you're talking about for the LT4.

i'm still lost on your whole headers melts stuff thing. i have headers, i don't melt stuff. please explain what the hell you're talking about.

 

I have headers on my damn Honda and if anything they help get the exhaust out faster and keep things under the hood cooler

 

Dude, google LT4, it shows the differences in the two, and yes 330 is real wheel horsepower, GM put intake, heads, cam, and bigger injectors on it and made thirty more horsepower over the LT1, I saw a Grand Sport in person my friend got, nice car. You need to do some research on factory specs before someone starts reading your wrong info on here.
And my headers are SLP mid-tube just like the FireHawk had, believe me they melt stuff!

 

dude...wrong answer. you're telling me a stock LT1 made 300HP to the rear wheels? anytime you see a factory give horsepower ratings, its ALWAYS at the flywheel. you can do your research a little more because i've done mine. ask anyone that knows anything and they will agree with me and call you wrong. STOP SPREADING BAD INFORMATION IN THIS SECTION.


perfect example...look at the OP's torque and horsepower numbers...273RWHP WITH MODS...so he mods it to go faster and magically LOSES 27 horsepower? wrong answer bro. do some research

http://neptune.spacebears.com/opine/horsepwr.html

read through there and you tell me who's right

 

Stock LT1 horsepower on a Vette was 300 and 275 on a Z-28 simply because of the better flowing exhaust on the Vette. And give or take a little weather manual or auto transmission. The Z-28's steel flywheel offered a torque increase in the manual over the aluminum in the vette's too. I have seen and driven most of the baddest American muscle cars built through the ninties, including Fords' Cobra "R" model. Not Dodge though because they were a little over the top with the V/10! But the fastest was the 1989 Turbo T/A V-6, it ran 11's stock, it was faster than the Syclone too, because of aerodynamics.

O' and most of the aftermarket stuff is just customization of the owner doesn't make real horsepower just true's it and keeps up with the milage and fuel changes that happen over time. Looks like the op picked up some torque? Most of us do not know how to drive'em anyways!

 

AT THE FLYWHEEL. read the link i gave you and quit arguing with me

 

a bigger cam will handle a bigger injector. takes about 32lb injector to make 400 rwhp. calls for a 30 but 30 doesnt really put out 30lbs. i think the lt4 did have 26lb injectors. im using 30s on mine now and they work fine. i do think the op has his issues settled on this thread.

 

Well my tuner told me to get 36# injectors and everything started melting! Now I am rebuilding.
I think that website was put out for the newer vehicles that are rated differently. Like on the new Camaro LS3 they say it has 426hp and their only getting 327 off the dyno's at the rear wheel. You have to know how to drive a manual. People with autos just hold the brake and burn the tires up, wow, I have never seen anything more stupid in my life. A clutch can be used to whip around a corner and when shifted properly (not on a dyno) will pull with it's torque far better than any auto could ever dream about!