stress fracture

My dilemma is I have a 6.0L gen III out of a “03” Chevy Silverado truck (LQ4). The engine is bone *** stock 4.00” bore & 3.62”stroke. It has aluminum heads the only numbers I see on heads are 317 cast into it. The engine is going into a “78” T/A 2nd Gen F body.

I’m aware the truck intake is too tall & want to put a Fast LSX 92mm intake on it, I was informed I would be better off putting a set of L92 heads on it, I would pay $895 for the LSX intake & $800 for a set of L92 heads, and would get much more performance changing the heads and installing a LS3/L67 intake on top.

My questions to you Guru’s is, am I better off going with the L92 heads & LS3/L67 intake, or just getting a Fast LSX 92mm intake?

Also when I do this I was thinking of putting in a GMPP Cam P/N 12480033 (intake 219 exhaust 228 duration with a 0.525” lift and 112 LSA). Unless ya all have better choice of Cams. The car will be a daily driver

Bandit28

iTrader: (28)

I would put a MS4 or Vindicator cam in it.

stress fracture

Got the p/n numbers & website?

GA95DCMSS

iTrader: (13)

I think that cam (GMPP Cam) would be too small for the L92/L76 combo. Gotta remember those heads have a HUGE intake port.

Gen414

iTrader: (38)

REMEMBER:
Truck motor, change intake, you are gonna have to change accessory drive!!!

That being said, what are your intentions? Power levels? How quick/fast? Without knowing what you want to do, there is NO way you can recommend a cam, or any other engine combo.

Let us know what you intend to do with the car and what your goals are

First Collision

iTrader: (13)

You're definitely going to need a bigger cam than that. http://texas-speed.com sells the MS4.

strokerblackhawk

iTrader: (4)

ok where do i start the fast 92mm will not work with the L92 heads fast is making one called the fast lsxr 102mm for ls3 and l92 or you could go with the LS3 or L76 manifold that uses a 90mm throttle body. the intake ports are totally different i have the fast 92mm with a PTM92mm throttle body and love it. id say check out that lsxr 102 i hear there suppose to be for sale sometime in april. and you need a much bigger cam something is the .23x's for duration and at least .60x's in lift id have it on like a 114-110 lsa.i like my **** to sound mean and still be able to drive it on the street

GA95DCMSS

iTrader: (13)

Not entirely True. Idler pulley relocation bracket. Search for it.

stress fracture

OK guy’s this car will be basically a daily driver, a street rod, It will be getting an automatic transmission 4L60E, 4L80E or a modified TH200R4 still doing research on which one to put in. I want to end up with around 500 HP.

I’m aware the accessory drive needs to be changed, & have a “98-02” Camaro/Firebird oil pan, oil pick up, windage tray, dip stick & dip stick tube due here in a day or so.

The engine has 30,000 miles on it so I don’t want to get into the rotating assembly. Just do Head / Cam swap, a set of headers & intake to get their.

Can ya recommend a good Cam Grind/Manufacture to go with? And a book to get on overhauling and maintaining the LS series engine.

frito1

iTrader: (12)

Chris Werner wrote "How to rebuild LS engines" It is a very informative and accurate book. Grab it.

It might be a little bit bigger pain to switch gears when you already have the 317's, but I would probably go with a L76 and L92's and get a cam to match that combo. Much more potential there.

stress fracture

Frito1, I'm leaning that way L76 intake and L92 heads can ya all give me a good Cam grind for this combo?

thirdgen60

iTrader: (10)

I have heard that the texas speed camshaft pn: 25-233239R2 , 233/239, .595"/.603" makes very good power with the L92 heads due to the duration split. From what i have been reading people that go much more on the duration with the stock 6.0L shortblock, start to lose power because the ports are actually to big. but you still want the exhaust duration to be comparable to what an ls1 head would want, which is why people are going with the duration split. Someone correct me if i am wrong but thats just what i have been reading.

ramdaspadhye

iTrader: (3)

Wow this is an old thread...

fwiw, after talking with a lot of the cam guys on here, it's best not to do the L92 setup on an LQ4 unless you're going FI due to the inability to get your compression high enough to run a large cam. If you had an LQ9, that would be different. You can mill the L92's, but you'd have to mill them WAY too much to get a proper compression ratio. I would suggest if you're on a budget to mill your 317's (same as 243's when milled) and have 'em ported, or talk to someone like TSP about some 243's ported and see if they'll take your 317's on exchange.

PREDATOR-Z

You can mill the L92s to .030 and get ~ 10.35 SCR (actualy LS3 heads would be better, lighter valves).
243s slightly milled will net you more compression (while still being able to put a decent size cam in there)
It all depends what you are trying to cahieve.
All these MS4 blablabla... are not suitable for a L92/LS3 setup. You need a cam specific to those heads, either custom or offshelf.
If you use the L92s I would say a high 22x/23x cam for that kind of compression.

78 TA has a shaker hood scoop, why not go with carb style intake with accufab TB and make use of that fresh air from the scoop?
I remember my 79 with Pontiac 400 (hurst 4 speed) and blade kit on the shaker scoop. I used to love watching those blades open and that thing twisting

yonerhottlt1

iTrader: (21)

Look, unless your tryna lower the compression for a blower setup I wouldn't go with the 317 heads. If you wanna go N/A or nitrous I would go with the L92 heads and an L76 manifold over a fast 92. And if possible, get the fast lsxr 102. But whether you get the heads and intake or not, the cam you listed sounds just like the gm LS hotcam which is way too small no matter which setup you end up going with. So pick a set of heads first, which the L92's are better flowing and higher compression than 317's, and then pick a good cam to support your setup

PREDATOR-Z

317s 71cc
L92/LS3 68.7 cc

not that much difference, works great on LQ9/LS2 but on LQ4 I prefer 243 casting milled.
Why> because you can fit a slightly bigger cam due to 2.00 intake valve. If 243s ported stage 1 (stock valves), you get 300cfm + better compression. (I hope this makes sense)

LSXNV

iTrader: (1)

i was just browsing and found this thread. i have thought about a setup similiar to this. i am of the old school mind set. though i am learning more and more about the new school. with this T/A (i am a pontiac guy and think i would rather see a trad. poncho engine in there but to each their own) why not go to a carb intake on l92's, with a carburator, and tighten the lsa up to bring the dynamic cr up? now i will admit i am not to intune with what the lsx's want out of there cams, but just a thought.

i have a 106lsa on the cam in my 462 pontiac. at 9.8/1 static it acts like it is a 11/1 or better because of the tight lsa.

i am interested in pred. z's take on this.

PREDATOR-Z

Well, it not a matter of just LSA. LSA is like a tuning tool, to cater the right valve events and of course more importantly overlap.
It all depends on where do you want to make the power in the band, and what use you have for said powerband.

ramdaspadhye

iTrader: (3)

Listen to Predator... He knows these motors pretty damn well!

And not to jack the thread, but predator, what do you think about the Thumpr cams with the L92 combo?

***** Thumpr
227/241 .563/.546 on 109lsa. I'm not sure of the ICL because the specs apparently aren't available on comp's website. Would this be an alright "off the shelf" cam for the L92 combo, or would you actually need more lift for the l92 heads to be efficient?


***EDIT***

Correction, here's the link to the cam card...
http://www.compcams.com/Cam_Specs/Ca...csid=1441&sb=0

103ICL, so 6 degrees of advance ground in.

ramdaspadhye

iTrader: (3)

bump this one up!