Steven Eaton

When I was pricing everything out, I was figuring that I would have to buy a new intake manifold and TB anyway, because I didn't think I would get the full potential of the ported heads with them on. So I guess if I don't have to buy those, it probably won't cost me too much more to just port the 317s. So say I do the 317s, here's what I'd plan on doing as of now:

226cc port package from AI
Flat top pistons
Aftermarket rods
ARP rod and head bolts
Long tubes
Stock intake and TB
Tune

Is the 226 package recommended? I know I will need injectors, do you think I can get away with standard 8.1 injectors? And about what cam specs should I be looking at, I might get a custom grind but I'm not sure yet. This is what I can think of off the top of my head, do any of you think I'd need anything else to make it work?

mcdonald77

iTrader: (21)

Having gone the l92 head route, My only other major mod would be a maggie unit. Told the wife to slap me if she sees my buying or looking at other mods at this point. If I did it over, some nice ported cathedral port heads it would have been.

96capricemgr

iTrader: (1)

Another point to consider is the OP is driving a truck that is literally a ton heavier than the f-bodies most here drive, maybe more.
Just because someone loves rectangle port heads on a 6.0l in a f-body with 3600 stall, and deep gears means nothing to the truck application. Tall tires tame gears, likely getting a lot less stall.
3.73s with a 26" tire is about the same as 5.00 with 37" tires.
4.56s/37" is about the same as 3.42s in an f-body but again the truck has a ton more weight to move.

OP what gear and stall are you considering?

Steven Eaton

My truck weights roughy 6900 pounds, it's got 4:10s with 35 inch tires. I don't know what stall yet because I dont know what mods I'm doing yet, I was going to decide after I figure everything out. I am leaning towards the cathedral ports now tho. I thought the l92s were going to be cheaper to do but it looks like it's going to be the same since I don't have to buy as much to make it work.

Tuskyz28

I would use a trailblazer SS intake over a truck intake..... especially if you leaning on the cathedral heads.

96capricemgr

iTrader: (1)

The TBSS intake is best I can tell just the 07+ regular truck intake with the bigger TB. GM engineer told me 6hp on an otherwise stock 5.3l.

I have seen guys claim 20hp but seeing as the factory engines didn't gain that with the intake, accompanying TB and VVT I would look at it as an upgrade just understand it is modest not earth shattering.
Often when folks add a larger TB they mistake throttle response from the extra flow at a given throttle angle for huge extra power.

Steven Eaton

Well I just realized that I never mentioned on this forum that this motor will NOT be N/A for very long after its rebuilt, so that might ease some of you who dislike the l92s because they don't have the proper velocity to make lowend power. I would sure think boost would help the lowend power substantially of the l92 heads. However from what I have seen the 317s also put out some impressive numbers when boost is thrown at them too, I might still stick with them.

gagliano7

Where is this thread in would like to check it out.

Tuskyz28

http://www.gm-efi.com/tech/btr-bumpstick-wake-call-blue-magic-finds-groove/

96capricemgr

iTrader: (1)

That is an important detail, but that said how would the boost be supplied? That will affect how it impacts lowend. A small turbo or a roots blower will make torque quick, a big turbo or a centrifugal blower will be slower to react.
For boost I would absolutely stick with 317s and the stock intake, don't waste money replacing those things.

Far as cam again how is the boost to be supplied? Ignorant folks will talk like a "boost cam" is a "boost cam" but turbo vs. supercharger is a HUGE difference in exhaust restriction that should be accounted for in cam specs.

Steven Eaton

I WANT to run a turbo setup, for many reasons. But at the same time I know they are harder to tune and can be less reliable than a supercharger. I think I am going to make it easier on myself and keep the stock heads and intake, they are going to get pulled regardless because I'm rebuilding the motor before I try adding boost, so I might still send them to get ported.

I know boost does better with lower compression. So would it be better to stay the dished Pistons and lower compression or switch to the flat tops and 10:1 compression? I'm not sure if the little bump up would hurt or help since 10:1 still isn't very high. Thanks again for the help

Tuskyz28

Call Chad Barton at CBI street cars. Maybe he can help you out. His tow vehicle is a 69 Chevy 4×4 408ci Ls3 headed turbocharged beast with a tooley cam. I have a pic of the truck in my phone but it's easier to screw Katy Perry than it is to post pics on ls1tech.