So I have a pontiac firebird 02

Setup
232/234 600/600 1.7 lift
Torquer V2 Camshaft
660 Dual valve spring kit
chromoly pushrods
Comp Cams Trunnions
3,000 stall converter
Longtube headers & axle dump exhaust
36 pound injections
roll-master timing chain
Stock/ Factory LS6 intake that came on the car
LSA 113


My question is should I port the 243 heads or keep them stock at 218 CC? I would like to make 30-50 hp so maybe i have to port them anyways but idk how far i have to go to make that much power, I’m also going to add some LS7 lifters & gaskets with ARP studs to keep everything strong & last long. And after that i want to spray 125 shot of nitrous. The goal is 570 plus wheel when everything is said & done.

right now the car makes 360-370 whp

 

looks like a nice fun setup. My only suggestion would be a higher stall speed converter.

 

That’s it? Haha the converter is going to be upgraded anyways.

 

Have them CNC ported, and milled to increase compression.

 

Port polish and milled..

I wouldnt run LS7 lifters, way too many horror stories on here. I'd run some high quality Johnson drop-ins (I have 2110s) or if you dont want lifter trays, some link bars.

 

damn for real 😧 what about ls9 lifters & trays?

 

If you're running dual springs like you noted above, I would stick with the Johnsons

 

https://www.corvetteforum.com/forums...0-lifters.html

 

https://ls1tech.com/forums/generatio...10-vs-ls7.html

I'm sure there are other brand options available but you need to have good lifters in a build like yours.

 

Okay sounds good

 

What is milled? & okay is that good for nitrous when you have a high compression motor?

 

if you're gonna go through the trouble of removing the heads you might as well have them ported, also as far as ls7 lifters are concerned I have heard some bad reviews on them but i've personally been running them since i did my heads and cam swap back in 2013 with no issues

 

Millling the head surface (removing material) reduces the effective chamber volume to increase compression ratio. How much depends on your starting point with chamber volume, engine displacement, gasket thickness, etc.

A bone stock factory 2002 Firebird LS is @ 10:1, which is still pretty conservative with 91+ octane.

 

gotcha 👍🏾

 

36lb will be very close to maxed out. The nitrous system you choose will have to be a wet system with 36'ers. Higher compression will be ok with the nx , but "tuning" window is smaller than a lower compression application. I am using LS7 lifters and have the preload set .055"-.060". My engine has the "sewing machine" valve train noise. I wish I had spent money on better lifters and at some point I probably will.

 

okay then what injectors should i go with? I was think a step up to 42-46lbs

 

I would definitely port them, send them off to Advanced Induction. They did some HCR 241's for a old Vette and the numbers were impressive.

 

Same here, 2 heads cam cars running them zero issues.

 

I didn't read if you already had the heads, but if you don't you might keep an eye out for some Cartek 4x 243's in the marketplace. 56cc Chamber, first heads to 500whp in an SBE LS1 F-body. They had a heads/cam/intake T/A running 10.3X's back in like 2009 with that Setup. I have those heads and am going to a 370, 14:1 comp E85. My car with the 4x heads and 2x cam made 470whp and that cam is a 228 cam. Required fly cutting to run the 4x cam. Now with custom pistons on the new combo, I can run a hawg *** cam!!!

 

dont have the ported heads yet but is it worth porting my stock ls6 manifold & throttle body? & what is the limit for porting the 243s? I have long tube headers by speed engineering