4.8/5.3 Boring
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Re: 4.8/5.3 Boring
Not sure how many on TGO have done it, but it's been done a lot on ls1tech. Most aftermarket engine suppliers use these blocks as the foundation for their 383 mills. (ATK, Texas Speed, etc)
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Re: 4.8/5.3 Boring
Yup, they put thick liners in the aluminum blocks and there is tons of meat in the iron ones. It ends up being .118 overbore. Texas Speed offers a re sleeved 5.3 up to 4.125 in bore. It's a versatile block.
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Re: 4.8/5.3 Boring
Things that make you go Hmm. I have a couple of LM7 5.3s. I also have (or will have soon) a set of LS7 heads from an LSX 454. Might be an interesting assembly.
Last edited by skinny z; 12-27-2019 at 02:16 PM.
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Re: 4.8/5.3 Boring
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Re: 4.8/5.3 Boring
Won't fit on a normal LS engine, bud. You'll need to go big bore (4.125" or more) to use those heads. $$$$$
From my LS7 head research a couple years ago, I think those LSX heads are already ported use the Lingenfelter CNC program. It's not a factory LS7 head. Good stuff right there.
From my LS7 head research a couple years ago, I think those LSX heads are already ported use the Lingenfelter CNC program. It's not a factory LS7 head. Good stuff right there.
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Re: 4.8/5.3 Boring
These are the heads in question. Still on the crate engine as purchased from GM but there's some Texas Speed stuff soon to take their place. The heads should be coming my way should I decide to make the move for them.
Thanks for the loan of the QUICKCHICKEN. And good luck with your project.
Thanks for the loan of the QUICKCHICKEN. And good luck with your project.
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Re: 4.8/5.3 Boring
Oh wow, I thought those heads were CNC ported. I guess not?
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Re: 4.8/5.3 Boring
I cruised the Chevrolet website and sure enough the LSX454 head is literally "as cast" and not CNC ported. There are CNC ported heads available (which I believe use the Lingenfelter CNC program), but the crate engine didn't come that way.
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Re: 4.8/5.3 Boring
The LSX454R was discontinued although the specs are here:
https://www.gmpartsdirect.com/oem-pa...ngine-19260835
The R version used a CNC'd port and chamber although I can't say if it was a Lingenfelter program.
https://www.gmpartsdirect.com/oem-pa...ngine-19260835
The R version used a CNC'd port and chamber although I can't say if it was a Lingenfelter program.
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Re: 4.8/5.3 Boring
Wow, that LSX-DR is so much different! It has a tiny 50cc combustion chamber with a massive 313 cc intake port volume. Definitely nothing in common with the factory LS7 head.
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Re: 4.8/5.3 Boring
This is really starting to explain though why the LSX454 is such a turd. It literally has stock heads and stock LS7 intake!
A 427 LS7 will gain +200 Hp with a H/C/I package. I'd think the LSX454 is begging for a H/C/I package to light the wick too.
A 427 LS7 will gain +200 Hp with a H/C/I package. I'd think the LSX454 is begging for a H/C/I package to light the wick too.
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Re: 4.8/5.3 Boring
Lookie what I found... 680 Hp from what I'm guessing is a ported AFR LS3 head that fits medium bore engines.
https://ls1tech.com/forums/dynamometer-results-comparisons/1891043-427-small-bore-engine-w-mms-260-ls3-heads.html
Did you notice how similar that engine is to the one I have for sale? I think I just found the recipe to make that engine scream.
https://ls1tech.com/forums/dynamometer-results-comparisons/1891043-427-small-bore-engine-w-mms-260-ls3-heads.html
Did you notice how similar that engine is to the one I have for sale? I think I just found the recipe to make that engine scream.
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