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5.3 forged pistons?

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Old Feb 1, 2012 | 08:37 PM
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Default 5.3 forged pistons?

I am building a lm7 5.3 twin turbo. My machine shop said they Cant find any forged pistons for the 5.3, "they have to be made" $110 a piece. I am in the dark in this so if someone can help me out I would appreciate it. I'm going for 9.5:1 compression ratio with twin garret gt3071r turbos. Ls6 cam and heads which I still need to buy so if anyone has some for sale let me know.
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Old Feb 1, 2012 | 09:50 PM
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Stock lm7 is 9.4:1 stock. I know a sponsor on here uses forged 5.3 pistons in there motors.
So i doubt they have to be made as custom.
The stock 5.3 has been known to handle alot of hp and psi on stock bottom end.
As long as tune is correct and everything else in line.
I trust my stock bottom end 4.8 to handle up to 1000. Since its low miles and in very good condition. Stock rings gaps,rod bolts. But everything else is fortified and prepped for ho psig and hp.
I can buold an hbeam rod forged piston 6.0, but i believe this 4.8 will handle it.
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Old Feb 1, 2012 | 09:54 PM
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Wiseco has a couple different 2618 forged pistons for 5.3L (3.780-3.800 bore) off the shelf.
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Old Feb 2, 2012 | 05:13 AM
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Summit has KB and Sealed Power and I believe JE in cast or forged also Scoggin Dickey has a large selection
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Old Feb 2, 2012 | 08:43 AM
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Thanks guys. I'm going to look into all that. Any links?
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Old Feb 2, 2012 | 12:25 PM
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I called summit, they told me that neither summit nor any of thier suppliers carry forged pistons for a 5.3. 96mm bore...
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Old Feb 2, 2012 | 01:27 PM
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Is boring to a 3.9 inches (LS1/LS6) an option for you? That would easily solve your dilemma. The iron LM7 would safely handle that bore even under boost. A sonic check will verify what I'm telling you. If you still want extra insurance and you're looking at high boost levels, you can always use a quality block filler like Hard Blok. It's very stable even for street use.
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Old Feb 2, 2012 | 01:59 PM
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Originally Posted by projectls2sc400
I called summit, they told me that neither summit nor any of thier suppliers carry forged pistons for a 5.3. 96mm bore...

http://www.wiseco.com/Catalogs/Automotive/Chevrolet.pdf
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Old Feb 2, 2012 | 03:11 PM
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Price isn't horrible when you compare the alternatives. Summit sells them for under $600. Thanks for posting that link.
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Old Feb 2, 2012 | 06:37 PM
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Thanks! Do Yall really think if I bore it out that it will hold up under 25psi making 1000 HP? That is my goal for this build.. but like I said I don't know anything about lsx motors so any advice is appreciated.
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Old Feb 2, 2012 | 08:39 PM
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I have all this.

https://ls1tech.com/forums/parts-cla...ock-parts.html

might part it out.
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Old Feb 3, 2012 | 12:41 PM
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Thanks js01! I just looked at the link! I think this will work! I'm going to give this to my machine shop.
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