ss_slowmaro

Ok, today i finally decided that i am going to start saving for a a project i've been wanting to do for a while.

I am going with a 6.0 iron block and having it bored to 4.030
Purchasing a forged rotating assembly

Now my question is i am wanting to run my 243's with my ls6 intake, i dont know if i will have to upgrade my fuel system. i would think so with a bigger displacement engine

I am also planning to run a ms3 cam, or do i need a bigger cam?

My main concern is my 243's not flowing enough and my ls6 intake constricting it to much.

If i am wrong on any of these please correct me
Any input is greatly appreciated

chase3

iTrader: (1)

people do run those heads and that intake and make ok power, but i would agree that you will be bottle necking a 408 with them.

KCFormula

iTrader: (4)

I have ported 243s on my 421 makes about 600rwhp NA. The intake will hold you back more than a good set of ported 243s. Ideally you should sell that stuff and go with a L92 head and intake though.

PAGregSS

iTrader: (10)

I have untouched 243 heads, LS6 intake, and ported stock tb on my 408. Power dies off pretty quick. The top end doesn't flow enough to keep up with the demands of the motor. It did make 448 rwhp through a 12 bolt. I knew the top end was going to be the restriction when I put it together, but I was on a budget. I am now in the process of shopping for a FAST 90/90 setup and getting my heads ported.

ss_slowmaro

Thanks for all the input, i may just step up on the heads but keep the intake since it will be easier to upgrade down the road.

Im looking to build a mild street car that can be daily driven with a few problems that i know will happen regardless.

So either get the 243's ported or buy some L92's. gotcha

Also will i need to upgrade the fuel pump or the injectors to handle the bigger displacement?

PAGregSS

iTrader: (10)

Yes, you'll definitely want some bigger injectors and a fuel pump. I'm running Racetronix 42lb injectors. 42lbers seem to be the standard with N/A 408s. If you do ported heads, you'll definitely flow enough to require an upgraded fuel system.