LT1-LT4 Modifications 1993-97 Gen II Small Block V8

LT4 heads?

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Old 09-02-2008, 05:04 PM
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Default LT4 heads?

I've got a chance at some nice LT4 heads that are stock with aftermarket valve springs and thats about it. The research I've done is that the LT4s actually flow a little better than the LT1 heads and they have a little more material to them so they can be worked a little more. my question is if I bolt those LT4 heads up to my motor with the cam I have in it would I see a little more gain than I would have with my stock LT1 heads?
Old 09-02-2008, 05:19 PM
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Of course, even if you had a stock cam you might not take full advantage of the heads but you will still gain something. With your cam you will see a good gain, and you can really take those LT4s to the NEXT level with porting...
Old 09-02-2008, 05:40 PM
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You want to bench race or talk actual performance??

Bench racers will swear the LT4s are great, here in the real world though you wont find a lot of 350s doing well with them.

The port is already pretty big which means it actually limits what a porter can do to them.

The hollow/sodium filled valves are awesome but other than that they are not that great.
Old 09-02-2008, 05:50 PM
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you seem to know your stuff. But would you see any gains such as like maybe 20-30 rwhp or would it be way less than that compared to stock LT1 heads. I figured if those heads actually flow a bit better with the larger cam wouldn't that allow you to make a little more power?
Old 09-02-2008, 06:07 PM
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Originally Posted by yardd0g24
you seem to know your stuff. But would you see any gains such as like maybe 20-30 rwhp or would it be way less than that compared to stock LT1 heads. I figured if those heads actually flow a bit better with the larger cam wouldn't that allow you to make a little more power?
Do you have an LT4 intake too?

I believe Dwayne is trying to save you a few bones; yes, stock LT4 heads flow better than LT1s but once you go to ported stockers the advantages dry up and with the LT4s you'll need a LT4 intake too.

IMO unless those LT4s are inexpensive I'd skip them and go to something better. PORTED STOCKER or PORTED Aftermarket

Mike
Old 09-02-2008, 06:08 PM
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More peak power yes BUT it will be lazier down low. They are better suited to very high rpm use if used on a 350. From the results I have seen on 7000+rpm strokers I am not even convinced they are that great a choice though.

Even most guys who believe the LT4s are great will tell you they are poorly matched to a fairly low rpm stock displacement motor.
Old 09-02-2008, 06:13 PM
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Originally Posted by yardd0g24
my question is if I bolt those LT4 heads up to my motor with the cam I have in it would I see a little more gain than I would have with my stock LT1 heads?
The answer to this question was yes. You will see something.

96 is very right though, if your looking for anything big in the future your better off spending the little extra on the ported aftermarket heads. Its just going to save you in the long run.

The LT4 kit is only designed for the hotcam, so your still going to be smothering that cam.
Old 09-02-2008, 07:07 PM
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I see very little application for aftermarket heads on the LT1 when ported GM LT1 castings work as well as they do. IMO ported GM LT1 heads are the best choice for most guys. Now if looking to go wild then the Trickflows in the right hands are the ticket.
Old 09-02-2008, 07:22 PM
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I just went through this process. I ended up having LE do his magic on stock heads. From everything Ive read unless you going all out stock ported LT1 heads will perform better than most people will need on a 350-383.

Now if your going all all out big bore blower turbos etc.... LT4s, trickflow, or AFRs seem to be the way to go over worked stockers.

AND YES you would see gains just by bolting them on your car, over stock unported LT1 heads



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