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L92 heads vs. ported LS6/317s

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Old Jan 4, 2009 | 10:02 PM
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Default L92 heads vs. ported LS6/317s

I'm kind of at a crossroads here, torn between two setups.

I can get ported LS6 heads from TSP for roughly $1000 and use those with the TSP 228r cam I have. They'll be a direct fit in my setup.

OR

I can get STOCK L92 heads. This would require the L92 truck intake, a mating of the return fuel to returnless rails, a 90mm cable TB (is there a bracket available for the cables?), and I guess a whole new intake tube/air box. I'd also have to sell the 228 cam and get another one suitable to the L92 heads.

So, which way would you go? The L92s seem to be producing great results with the right cam, but I'd have to change up so many things. The LS6 heads would be much more simple to set up, but I'm not sure the potential is as great as the L92s.
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Old Jan 4, 2009 | 11:10 PM
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this might be a dumb question but, do they even have cable throttle bodies that bolt up to the l92 intake yet?

if so, what intake are you using right now? having the ability to bolt up a 90mm throttle body would be nice to have but, i wouldnt think for all the trouble that is gonna come with setting up the l92 would be worth the difference over the ported heads.
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Old Jan 4, 2009 | 11:36 PM
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several companies make 4 bolt 90mm cable tbs
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Old Jan 5, 2009 | 09:33 AM
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look around I got my fast 90mm dbc tb for $200 and all you have to do is make a bracket to hold your stock cruise control line and throttle cable to the bolt on the l92 same as what i have with different runners
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Old Jan 5, 2009 | 09:36 AM
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I say go for the ls6 heads, less work to put them on, go. Plus I don't think the 92's would net you much more if any then the 6's
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Old Jan 5, 2009 | 11:23 AM
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I'd go with the 243's ported. The L76 & L92 intakes are limiting on the top end. I think an LS6 intake would flow better and you wouldn't loose the low end below 3000 that you do with the huge runner of the L92's.
If I had the time or the money, I'd swap on some ported 317's and a FAST 92 just too see the difference.
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Old Jan 5, 2009 | 11:25 AM
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I ordered stage 1 317s milled to 68cc from TSP this morning.

What all is involved in the FAST 92 swap? I've seen a dyno on LS1tech where a guy swapped to the ported fast 90 or 92 can't remember from an ls1 intake and got 44rwhp
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Old Jan 5, 2009 | 11:31 AM
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Originally Posted by GMCtrk
I ordered stage 1 317s milled to 68cc from TSP this morning.

What all is involved in the FAST 92 swap? I've seen a dyno on LS1tech where a guy swapped to the ported fast 90 or 92 can't remember from an ls1 intake and got 44rwhp
I would wait till we all see how the new Edelbrock works.. Looks badass, is way cheaper then the F A S T setup.
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Old Jan 5, 2009 | 11:32 AM
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Fast 92 is the updated fast 90. you can't get the fast 90 anymore. It isn't for L92's it is still cathedral port they just sell a 92 mm TB you can put on it.
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Old Jan 5, 2009 | 11:36 AM
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I see you're running 8.8:1 DCR

If I went with LS6 heads my DCR would have been about 8.5:1 or so. This was too high to run 87 safely if i had to? So the 317s milled to 68 will yield 8.2:1 DCR. The guy on the phone said he'd be surprised if there was more than a 5hp difference between the 2.
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