My go setup is basic right now. Pacesetter LT's, custom exhaust with Spintech super pro street mufflers, Svede speed OTRCAI and HP tuners.
Yesterday, I received the estimate for the spring build. MSD Atomic intake manifold, Nick Williams 102mm throttle body, Texas Speed LS series custom (.233/.239/.500) rough idle camshaft and dyno tune.
I asked the rep from the performance shop what about heads as far as performance gains and I was advised they don't give that much and that it is the cam that does.
Is it worth adding a set of aftermarket heads?
Also, without the heads, what hp/tq gains can I expect from the new mods?
Not trying to be short. If I were you I would find another performance shop. A real performance shop could answer all your question. Heads and cam will add plenty horsepower.
Probably loosing about 25-40 RWHP from not changing the heads, but I am no expert. I would assume you should still gain about 60-75rwhp without the heads.
I would get some aftermarket heads since they are working on the engine anyway. I am getting the CNC Stage III LS6 heads.
if you dont want to spend that much you could send your heads in to tsp for a 2.5 prc cnc porting service its about 950 with new ss valves that is the last step to mine before i add nitrous i already have cam package 92mm fast svede tsp longtubes and all the little things to go along with it i like all motor also hoping to get about 60 70 rwhp at least just mentioning the head porting because its not as expesive good luck with your build!
Hope they do more than dyno tune it. I also hope they know how to dial in that giant TB correctly. Not easy to do on the 04's. You sure you need a TB that big? Who specc'ed out the total package for you? What are your desired goals?
*Might be scrapping this build for now*
This afternoon, I received a call from the dealership I have been waiting for. They finally got in a 2017 Chevy SS, Slipstream blue metallic/6MT.
I've been wanting this car.
If I get the deal I am looking for, I will get the SS.
If not, continue with the build.