More cubes opens up more NA performance. 383... or find a 6L block and do a 408. Beyond that, you start getting into more expensive options and the gains are less and less as the heads need to be upgraded as you move to a 416/427 type of realm.

 

If 30# are good for 500 rwhp, then 26.6 # should be good for about 441 rwhp if my calculations are correct. I think I'm just going to run my stock injectors and see how it goes.

 

26.6 is good to about 420rwhp.

28.8 is good to about 450rwhp.

You might be able to push more, but I've never really seen anyone take the 28s past 460. Most are at 100% duty cycle around there too, which is not good.

 

30# SVO/Ford Injectors are
Rated @ 3 Bar ~44.5 PSI
GM Pressure is 4 Bar ~58PSI
=36lbs, I believe there are
Some 3800 V6 supercharged
Injectors that are 36lbs @
4 Bar also that Tuners like
Very well and are Cheap!
I would absolutely recomend
36 lb @ 4 Bar for your
HCI Build!

 

Will the 36# injectors be dumping too much excess gas into the engine...assuming I will only need about 28-30# injectors? I'm only assuming I will get 420-430 rwhp....I'm hoping for more though.

I'm considering putting larger valves......2.02 intake and 1.575 exhaust. Do you think this will give me any performance increase over the factory 2.00 and 1.5s out of a C5 corvette with 243s?

I was told the factory valves are good valves and lighter than the truck valves.

 

The SVO 30s @ 3-bar or the GM 36s @ 4-bar... that's what you want.

You won't dump excess fuel if you tune for the injectors. You will if you don't tune them.

 

Ok. I'm going to get the 30# svos, and yes they will be tuned.

Is it worth upgrading to 2.02 and 1.575 valves while the heads are being worked on?

Will that give me a noticeable increase in hp/tq? Also, will that cause any daily driving issues?

 

Wont cause driveability issues, I also wouldn't bother with it.

 

The guy I bought the 243 heads from, said they came off his 05 vette, but it is not Z06.

Do these 243 heads possibly have the hollow stem sodium filled valves?

 

Probably not. The hollow-stem valves only came on the Z06 and the first gen CTS-V (I believe - engines designated LS6). The LS2 got 243s with standard valves.