LT4 head swap?
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From: Kennesaw, GA www.96LT4.com
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St. Jude Donor '03 thru '26
LT4 head swap?
I'm out of my league here, so I need some help. Trying to get more out of my already modded LT4. With what is listed below, what are your recommendations without breaking the bank?
Current mods:
LT4 hot cam
Exotic Muscle long tube headers
Random tech high flow cats
Corsa exhaust
Mezziere electric water pump
Custom tune by Trifecta Perf
Nothing has been done to the heads or intake other than swapping out the springs and adding valve guides.
She put down 341 rear wheel horsepower...trying to get to 380-400.
I do not want to go back in and change cams...major pain in the butt.
Current mods:
LT4 hot cam
Exotic Muscle long tube headers
Random tech high flow cats
Corsa exhaust
Mezziere electric water pump
Custom tune by Trifecta Perf
Nothing has been done to the heads or intake other than swapping out the springs and adding valve guides.
She put down 341 rear wheel horsepower...trying to get to 380-400.
I do not want to go back in and change cams...major pain in the butt.
Melting Slicks
Joined: Oct 2006
Posts: 2,238
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From: College Station TX
Porting your factory heads and intake could get up you up around the 380RWHP mark, give or take, with that cam. With a bigger yet still streetable cam, 400-415 RWHP is very doable.
But nitrous would be the cheapest and easiest power adder by far.
But nitrous would be the cheapest and easiest power adder by far.
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From: Kennesaw, GA www.96LT4.com
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What I have bee told on porting the LT4 heads is that HP goes up, but torque goes down.
Nitrous...anyway to add it without having lines everywhere? Direct port so to speak?
Thank you for the help!
Nitrous...anyway to add it without having lines everywhere? Direct port so to speak?
Thank you for the help!
Race Director
Joined: May 2003
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I would think so since the LT4 head starts it's life as a 195cc head. A few yrs back my friend ported his heads, and I thought the car felt slower. (stock cubes).
Melting Slicks
Joined: Oct 2006
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From: College Station TX
I think it's all in the combination. Call Lloyd Elliot, tell him what you have, what you want,and he can hook you up. My 383 with ported factory LT4 heads has 425 RWTQ.
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Remember that Ron has some brand new cylinder heads for sale in the parts section. He is selling them so cheap, it might be practical to use them, if you are opting for porting.
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From: Texas
Just remember that with nitrous...it only lasts as long as the bottle has something in it and to mount that bottle in a C4 you're going to have to drill some holes for mounting brackets and lines. Guessing you don't want to do that.
Safety Car
Joined: Sep 2000
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From: Hinckley Ohio
.....My heads were "pocket ported" by a skilled craftsmenYou bet the horsepower went up...390RWHP on stock 350 bottom NA!!!
Few other mods but still 25MPG highway..
I did not see any reduction in torque at any rpm...
There are other heads out there but porting the stock heads is a reasonable option if you deal with someone who knows how what they are doing...
..BTW it seems about the most people get with the hot cam is around 365RWHP...to meet you goals you might want to consider a more modern slightly more aggresive cam....I used CompCam 503, but there are better cams out there now.
Last edited by LT4BUD; Dec 16, 2009 at 10:31 AM.
Melting Slicks
Joined: Mar 2004
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From: Pittsburgh Pa
Melting Slicks
Joined: Mar 2004
Posts: 2,141
Likes: 2
From: Pittsburgh Pa
Melting Slicks
Joined: Mar 2004
Posts: 2,141
Likes: 2
From: Pittsburgh Pa
Melting Slicks
Joined: Mar 2004
Posts: 2,141
Likes: 2
From: Pittsburgh Pa
not really.. if he already has an lt4 he would either have to buy an lt1 intake manifold or machine his stock intake which would be a unwise move. he would be better off having his stock heads ported by a professional.
Race Director
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I said it was an option. What can possibly be so different between an LT1 and LT4 intake? Educate me rather than correct me.
Melting Slicks
Joined: Mar 2004
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From: Pittsburgh Pa
LT4 heads have a taller intake port. the lt4 and lt1 intake in stock form have the same cast port but the lt4 intake has more material that allows for proper port matching of the taller port. LT1 heads have a ridge on the intake gasket surface that wont allow the LT4 intake to be bolted to it unless its machined. this is not the greatest pic but the LT4 intake is on the left and LT1 is on the right. draw a line down all the bolt holes.. now see the distance from the edge of the port that would be closest to the valve cover.
Thread Starter
Team Owner
Joined: Jan 2000
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From: Kennesaw, GA www.96LT4.com
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Ugh...I hate this not knowing situation.
I want more power, not a lot more, just enough to pull me even with the C6 numbers.
What's funny though, the few times I've run with a C6, I pull them.
Still, I'm wanting about 20-30 more RWHP.
I want more power, not a lot more, just enough to pull me even with the C6 numbers.
What's funny though, the few times I've run with a C6, I pull them.
Still, I'm wanting about 20-30 more RWHP.
Safety Car
Joined: Sep 2006
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From: Pasadena CA
Porting is definitely one of those dark arts where it needs someone who knows what they're doing as stated. If I had your build I would do this next and then another re-tune. Or porting plus a new cam and a re-tune