Will I benefit from them? I currently have a lid, maf, intake, headers, and gears.

 

no....


heads and cam...yes

 

You'd benefit more from traction judging by your ET vs trap speed.

 

Yeah tell me about it. The reason I asked is that this guy has some larger injectors on his Z and will basically give them away to me. I just didn't know it it's worth it or not.

 

if they are close to free, take them. dont know how true it is, but im told one of my issues with bad performance after h/c is that 2000's have the smallest injectors in '98-'02 run. i just 42#ers

 

Smaller injectors means little at this stage. The duration or pressure can be adjusted to make up the difference. It also depends on how big these other injectors are. Too large can hurt performance.

 

Yes they will be a plus even with a stock engine for it would help engine from going lean enough to trip knock/ping and lose timing when its needed such as during PE mode going to WOT.
With a PCM tune in using such as the SVO 30 injectors will also allow even more timing being tuned in.

Consider a C5 Z06 uses 28 lb injectors and the new C6 with same HP and Tq now uses a 33 lb injector.

 

You're not going to make more power by having bigger injectors, no. But if you plan on H/C, spraying, forced induction, or hell all of that, then yes you will need bigger injectors, unless you want to starve the car of fuel

 

Ok so you're comparing the fuel needs and out put of a larger engine to a smaller one? The fact that a smaller (346 cui) engine makes the same power (actually a bit more) with smaller injectors vs a larger (364 cui) engine with larger injectors would go against the concept of larger injectors making more power.

 

It makes no difference if one engine is slightly larger cubes the fact is the stock injectors with a 80% dutcy cycle max out at 340 HP, period and because of that the injectors fall behind and cannot catch up at the top of the powerband.

I have tuned 100s of LSxs, most went with SVO 30 injectors and even a stock engine with the SVO 30s have good performance gains.

example just today at the Vette magic drags in Sac Ca a stock C5 with injectors and my tune went from 13.5 ETs to a 12.9 so its not that a stock injector will not work its with them you cannot tune to get the maximum ability of the engine.
For $230 a set of SVO 30s that is a good performance gain.

 

Just putting in 30lb injectors is not the same as doing a tune - another $300 to $500, above the $230 - w/injectors ...

I suspect that the 12.9 vette had less to do with the injectors than it had to do with the tune and I would hope that car was dead nuts stock other than the tune - otherwise that 12.9 is about as impressive as 13.5 on a C5 is.

 

But you still compared a smaller engine with smaller injectors that makes more power with a larger engine with larger injectors to prove your point. That comparison totally goes against your point.

As stated above, $230 for injectors + how ever much you charge for a tune. Thats probably over $700 for all. Go through that expense, get a cam while you're at it! Plus the ET proves little without the same conditions and driver skill. I've seen people pick up over .5 sec just because they had time to get used to their car.

 

Update - as opposed to the stock Z06 - on stock injectors - that went 11.8s on a competitors tune ...

 

I would say on a slightly modded LS1, another less than 350 RWHP(full bolt-on), your stock injectors will do its job. However, anything over 350RWHP you'll definitely need larger injectors, probably a 30lb. for anything up to 430 RWHP.