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Why would an LS2 or LS3 be preferable to a 97-04 LS1 Engine ?
Full 5.7 Displacement...
 

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In NA alloy, while the LS1 is a great engine, with a couple exceptions, higher the LS "number" the more basic power and the potential for power. Unfortunatly the price goes up too..

The small bore LS1 limits valve size.
As in you can't put LS3 heads on it like you can with the LS2.
That said you can make pretty big power out if a cathedral port LS
The bigger 6.2 LS3 , they make 370-380 at the wheels BONE STOCK³
 

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Well the trend is to LS it! I think I've even seen a T-shirt saying that somewhere. :rolleyes:

While that's not my favorite option, I'm a glutton for old-school (punishment) and would rather rebuild a LT1 or even a pre-LS Vortec SBC into a 383 than drop an LS into it. The problem is that depending on your regional knowledge base, the old school engines are 25+ years old. LT1s were always stepchildren and oddly seemed difficult for the even-older school guys to wrap their heads around when they were new. Whereas you can find LS knowledge everywhere. Once the LS came out, most people never looked back. Just go to any local race track and get to know people. Granted in most ways, the LS is a superior platform. But I personally just like old school... the caveat is finding the local resources (ie: machine shops, builders, etc) to support old school stuff.

That said, in this day and age and proliferation of parts and knowledge regarding the LS platform, that can be one of the cheapest solutions, especially if you don't want to build it, but rather just swap it. For swapping, well, don't forget truck engines, you can get those on the cheap everywhere... and for a little more, build them up without needing to source a real LS2/LS3.

Here's a good resource for that...

 

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storm9c1 has a good suggestion for the LS truck engines. The only problem is the money it will take to bring up to factory performance LS engines. Good thing is the truck LS engines are designed for more bottom end torque to pull around very heavy vehicles (over 5000 lbs) and trailers. Not a bad option for a 4000 lb plus Impala. If I had a choice and wanted a strong engine but not a quarter mile monster, I would keep the LT1 and do a quality rebuild with LT4 aluminum or aftermarket heads. You can do major work to the cast heads but wind up with spending as much as buying new aluminum heads that are bolt on ready to go. Need to do a VERY close inspection of new heads. There is a u-tube video of a person inspecting new aluminum heads right out of the box and finding all sorts of problems. I don't trust anything I buy and do a close inspection of EVERYTHING. Also, be careful of counterfeit parts. Amazon and ebay seem to be full of those. Research is everything!!! Good luck for any way you decide to go.
 

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In NA alloy, while the LS1 is a great engine, with a couple exceptions, higher the LS "number" the more basic power and the potential for power. Unfortunatly the price goes up too..

The small bore LS1 limits valve size.
As in you can't put LS3 heads on it like you can with the LS2.
That said you can make pretty big power out if a cathedral port LS
The bigger 6.2 LS3 , they make 370-380 at the wheels BONE STOCK³
Thank you 95Wagon for the explanation of the LS platform steps in advanced design.
I tried to delete that post almost immediately afterwords, but it wouldn’t let me.
I did the research and found out what the higher numbers meant as well, which ones were the more desirable (and expensive) ones...
And of course your info is accurate for those specific LS platforms mentioned.
Any engine I might consider for a CA legal swap has to be of the same displacement as the stock engine or less.
So I was looking to the LS6 platform from a Z06 Vette as a potential candidate.
The use of ‘Truck Engines’ as being a good option also was mentioned here..
I still thank you for your help and information!
Is there a 5.7 L LS platform you would recommend for me ?
Your time is always appreciated, I know how busy you are sometimes...
 

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I would have to defer to the CA guys for recommending legal swaps.
I do not know what steps they take in identifying what your engine is .
If it is serial or block casting numbers, I will say , the world is full of 400++ cubic inch engines based on ls1 blocks!!
Where i am , they dont care about cubic inches.
The emission spec did change during testing though.
My gripe was , where in hell did they come up with IM240 specs for a 1995 7.0 manual trans Caprice.

The iron vs aluminum.
Yeah, iron is cheaper, and more stout for big power, but I do like having a car that weighs less on the front than the back
 

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Why would an LS2 or LS3 be preferable to a 97-04 LS1 Engine?
Full 5.7 Displacement …
Unfortunately for kalephonyans, the only 5.7L blocks are LS1 and LS6. If the casting numbers do not correspond to either an LS1 or LS6 block, there's gonna be problems.

Once free from kalephonya's persnickety particulars, any 6.0L or 6.2L Gen3 or Gen4 engine becomes very preferable.
 

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.….Any engine I might consider for a CA legal swap has to be of the same displacement as the stock engine or less.......
Man.....you could put a 427ci LS engine in your car and an inspector would never know.

ALL....LS engines are the same, externally. The only hint as to which engine you have would be the intake manifold.

Just make sure that your intake matches your heads....and your heads will work with your short-block.

KW
 

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I was under the impression that blocks & heads since 1996 have casting numbers to identify and differentiate them, if only because blocks & heads prior to 96 had casting numbers for the same reason and purpose.

This is another situation where I'd love to be wrong!

Given the fact that 5.3L, 5.7L, 6.0L, & 6.2L Gen3 & Gen4 V8s ALL share the exact same 3.622" / 92mm stroke, thus the given fact that the block / bore chosen determines displacement …
if no inspector can tell any block apart from any other, then get the biggest block you can afford!
 

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Fortunately I have some time to make that final determination. The swap is as of right now not in my financial budget, and will have to wait a few more months before even plausible.
I thank you both for the relevant information and the time you took to respond.
Thank you !!!
 
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