I am looking at getting a 408, but I don't have the extra money to change my ls6 intake or my stock manifolds, how much will this hurt me hp wise? Should I expect somewhere around 450rwhp? I would think it should be able to get that in my car, what do you all think?

The engine has:
Stage III Patriot LS6 style heads with 2.08/1.60's and patriot dual springs, 62cc Chambers
Comp 244/248 .612/.615 113lsa cam
10.7-1 CR

 

It will hurt you biiiig time, the stock manifolds more then the intake.

 

The stockers flow decent enough, you'll be ok. You already know you power will be compromised a little but it won't "hurt" anything. Upgrades are done in steps. You start with the foundation and build up. Your looking at it the right way. Solid shortblock to start then add to it as budget permits. Cant honestly say what rwhp your looking at though, but it certainly wont be a dog.

We build stout 408's, I'd be more than happy to write a quote for you.

 

I would be doing the other boltons first, but I've come across a deal that I can't pass up. So, with that in mind, back to the question. How much hp will the stock manifolds be holding me back? 20? 30? 40?

 

Has noone done this before?

 

you cant budget 200 bucks for headers and 300 for an ls6 intake but your buying a 408?

 

i did this on my vette, i put down 460 RWHP with an LS6 manifold and stock Z06 exhaust manifolds. i was also on stock injectors as well.



im running hogged out ls6 heads and a koneig 408.


switching to a FAST 90/90 setup netted me an extra 7-8 MPH at the track

 

If you can afford the 408, save up another month and buy some LT's before you put it in. I don't know exactly what manifolds would do to a 400+ cubic inch motor but I have seen the way they kill a heads/cam car and there is NO way I would put manifolds on a big cube motor. If nothing else, throw a set of uncoated Pacesetters for the time being. You will be happy you did.

Jon

 

I was looking on your site at getting a 418 for my 2002 SS. Guess a manifold wouldnt do it for the 418. What would you recommend for the intake setup? And how much RWHP and RWTQ do those make?

 

I would deff wait until you had the money and buy a nice set of ARH. To me if your not gonna do it right just dont do it at all. Stock manifolds and intake will KILL you power. stock manifolds and stock intake i bet you would be down a good 50-70rwhp

 

PM Sent!

 

The headers I want are the 1-7/8" headers by Texas Speed, $479, and I have an '01 so I have the LS6 intake. So where do you get headers for $200? I am stretching my finances to get this engine, but I couldn't pass it up. It will be in next week, I'll have to dyno it and see how it does.

 

So are you budgeting in a tune as well? Buy the shortblock but wait to install and tune for the headers i would say. You can run it if you are dead set on it, it will just not be entirely optimals. Are you running stock exhaust and cats? Alot of the turbo guys run stock truck manifolds so i cant imagine theyd be too bad. They are no where near as bad as stock LT1 manifolds from what ive seen.

 

FWIW..... i also skimped on my tune for the first month or two.... as in i ran my cammed 408 on the stock tune.. my 450 RWHP was on said stock tune

 

The guy installing it is going to tune it as well.