Stoichiometric

iTrader: (10)

Thanks for the advise guys . 8ALTNG, what problems did you run into at 18psi? I am not hellbent on getting to a boost level, I am more concerned about getting the most out of my combination. I will have a 90mm throttle and Vic jr. on top of WCCH 245 Edelbrock heads. I will also pick up an 88mm turbo, either Precision or Turbonetics and an air to air intercooler.

EXTREME

Stoichiometric, are you going with a certain turbo system or building your own?

TurboBerserker

iTrader: (1)

I run 8.6:1 and built for 18-20psi with meth and an intercooler.

15psi will put you solidly in the 700s to the ground.

That cam is way to small for a 408 IMO. I run a 236/230 on a 115 lsa with no lope. The cubes will eat a lot of the cam.

Stoichiometric

iTrader: (10)

EXTREME, I am building my own. There are only so many ways to plumb a front mount single, so you already know about how it will look.

TB, 700s to the ground would be cool ! The cam you mentioned is exactly what I originally wanted to put in my 408, after talking to a couple people I though that I could afford to scale it down a little. How does your truck respond on the street with your cam and that boost level? Your set-up sounds very close to what I want to build.

TurboGibbs

iTrader: (6)

Since you are wanting a solid daily driver i'd keep it at or below 15psi max on 91 octane and shoot for the 8.5 - 9.5:1 range. There are a lot of variables but since you already have pistons and heads 8.5 is about the most you could stretch the compression to starting with 8:1. The Edelbrocks do have a thick deck surface so milling them is still an option. Over 12psi on stock gm heads and you start to run the risk of lifting the heads and getting a little leak off from what i've heard of and done personally. Never caused any issues with me but I could see the carbon from exhaust reach past the head gasket bead at the edge of the cyl. That was with stock GM multi layer steel gaskets which are really good. One of the cases where racing technology has made it to the production vehicles.

Stoichiometric

iTrader: (10)

TurboGibbs, would you reccomend a GM mls gasket for my 408? It sounds like the way to go if they make a 4.030". I don't actually drive this truck everyday, it mainly get used on the weekends. I want to keep myself in check so I could drive it everyday if I wanted to. How much would a higher stall converter buy me for low end torque if I were to keep my 8:1 c.r.?

Lurius

iTrader: (7)

I know you werent asking me... but go with some cometic gaskets. They have .030, .040 .0450, and .051 for the 6.0l blocks. Look at texas-speed.com for some.. they are under the camaro section i think.

-Lurius

1slow01Z71

iTrader: (36)

You cant run a GM gasket with a 4.03 bore. I run cometics and so far am happy with them and alot of other people really like them too.

Stoichiometric

iTrader: (10)

Thanks, I will check them out. I have used Cometic gaskets on my dirtbikes, I would like to use them on my truck too.

TurboBerserker

iTrader: (1)

Er... Been running MLS for 2 years on a 4.03 bore They work great, don't lift, etc. I do have head studs and have 'em overtorqued 15 ft/lbs however.