68BBChevelle

iTrader: (12)

Looking to do heads and cam on my LQ4. Just not sure which direction to go Ls3 top end with these cnc heads. http://paceperformance.com/i-7139127...-assembly.html

Or send in some 243s to AI and top it off with my Ls6 intake. Opinions.

I know i will have to get a different intake for the ls3 heads.

68BBChevelle

iTrader: (12)

Anyone?

Tainted

iTrader: (9)

Personally, I prefer the cathedral setup on bores smaller than 4.030. The intake valve is slammed right up against the cylinder wall for the ls3 heads, hence my preference. Not only that but unless you are willing to flycut the pistons then you are limited as to how much milling you can do, and how large of a cam you can run.

onefast84

I did a lot of research and fount that the 243 is better for a stock bore 6.0L. However if you are planning a future build of a bigger bore. Than you might consider the ls3 heads. My lq4 screams with stage 3 ported 243's. You wont be disappointed!!

68BBChevelle

iTrader: (12)

Im just trying to figure out whats the best bang for my buck. And how much power difference there would be between the 2 setups?

68BBChevelle

iTrader: (12)

I would like to do a 408 down the road but this would have to blow up first before i would commit.

Tainted

iTrader: (9)

Id stick with ls6 heads then. You can run a bigger cam, mill for more compression, wont have to flycut, and the ported ls6 heads would do every bit as good or better than the ls3 heads.

anheuserbusch08

iTrader: (11)

95% of the time u run around 2500-5500 rpms. 243s give better midrange than l92s on a 6.0, run the 243s u wont be disappointed

68BBChevelle

iTrader: (12)

how much would i have to mill to get around 10.5 Cr? I would like to pull around 450-475 rwhp. I would only spin it to 6500.

Tainted

iTrader: (9)

with cathedrals you could mill even more for higher compression. stock ls3 heads are 68cc vs ls6 @ 64cc

**in general .06 = 1cc

PREDATOR-Z

You could compromise. Install 2.08 /1.58 valves on the LS3 heads and that will complement the 4 inch bore pretty nicely.
That with the right cam would make some stout power.

68BBChevelle

iTrader: (12)

The ls3 heads im looking at are not stock heads the have already been cnc'd and have a 2.16 hollow intake valve now. Why would i want to go to a 2.08? check out ls3 head link in 1st post.

Tainted

iTrader: (9)

those cnc ls3 heads are going to have an even larger runner and youre losing velocity. it'd be fine if you had an intake that flowed as well as the heads and a motor that could use the air, but in your case I dunno...

predator certainly knows his stuff, and TEA can do the work predator mentioned to the ls3 heads. I checked on it for my 408 and I wanna say it was about $1800 including the castings.

KCS

iTrader: (20)

You still have a big *** port on the LS3's, even if the valve is only 2.08". I'd say mildy ported cathedral ports for sure, especially since you're putting a T56 behind it. The cathedral ports almost always make better overall power than the LS3 heads,

Tainted

iTrader: (9)

Finally I feel vindicated somewhat.

bww3588

iTrader: (49)

.006

Sorry Charlie.

Tainted

iTrader: (9)

Decimal points, one more reason I alwaya got a D in math

68BBChevelle

iTrader: (12)

Thanks for all the advice and help fellas.