One more time 317 vs. L92

[JJAB]

Okay guys, I know this has been discussed and I also know that there are a million variables that are to be considered. The sad part about this is that I have not made my unltimate decision on what vehicle I am putting this in, but here goes.

I am trying to decide between ported 317 castings vs. stock l92 plus ls3 intake. My goal is to make 350 to 375 RWHP. The mill is a LQ9. All other things considered are the vehicle will have 3.73's, headers, it will stay fuel injected, 2200 to 2500 stall. I have a cam laying around that spes out at 218/228 @.050 and .525/.525 lift @.050.

[Clyde65]

A stock LQ9, with a mild cam, headers and good tune, should have no problem making 375 RWHP I would think.

[Shon]

your goals are low if you are looking at ported heads in either variation. I have several almost 400 to the wheels with just a cam in 346s/LS1s and I have some almost 500s with LS3 heads/cam/LS2.

I am a bigger fan of the cathedral heads if you going for MPH at the track but if you just want to make power it can be done with either set. I have seen cathedral heads run quicker at the track in comparison to the retangular ports and I am not sure if thats a mismatch of cam/heads or just better air flow from cathedrals.

I have a customer with a 23x/25x cam with stock LS3 heads/intake making nearly 500. He also has a 01 Z28 that makes almost 400 with just a cam.

The retangular heads are 'cheap' but there is more to it, you have rocker arms to get, intake to get too. so the cost goes up.

And that cam you have would be better suited for the cathedrals, the I/E split is not enough for the retangular heads from what i have seen, and if you want to sale that cam let me know, we love that cam...it makes great torque and helps with our 'tow' packages.

[clinebarger]

Originally Posted by JJAB

My goal is to make 350 to 375 RWHP.

A well tuned STOCK LQ9/4L65E will make those numbers.

[JJAB]

Thanks guys for your input. Your information has helped me make my decision.

[softballnrd27]

No reason to port or change the 317s, get a good valve job and you should very easily make your power goals. If you want a little more power, get a little bit more cam.

[BR3W CITY]

Originally Posted by softballnrd27

No reason to port or change the 317s, get a good valve job and you should very easily make your power goals. If you want a little more power, get a little bit more cam.

porting the 317's won't hurt, a little more flow is always a good thing
I just wouldn't mill them or do anything to raise compression any more on an lq9

[mooseknuckles]

http://www.carcraft.com/projectbuild...k/viewall.html