Block casting # 12571048. 5.3

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Dec 9, 2017 | 12:58 PM

Fishmasterdan

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Block casting # 12571048. 5.3

Picked up a motor for cheap. It has 243 heads on it with flat top pistons. I want to build and replace my LS1 Vette motor. Looks like all the sensors are different?
Can these blocks be bored to LS1 size? Or new sleeves?

Dec 9, 2017 | 03:34 PM

G Atsma

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From: Central Cal.

The sensors are different because it is likely a Gen IV engine, where yours is a Gen III. Is the engine an iron block or aluminum?

Dec 9, 2017 | 09:20 PM

Che70velle

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From: Dawsonville Ga.

Quote:

Originally Posted by G Atsma

The sensors are different because it is likely a Gen IV engine, where yours is a Gen III. Is the engine an iron block or aluminum?

That casting number shows it to be an aluminum block G.

Dec 9, 2017 | 10:12 PM

G Atsma

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From: Central Cal.

I understand aluminum 5.3 blocks can be bored to 5.7 bore size without any problem.
Thank you Che70velle!

Dec 10, 2017 | 07:21 AM

Fishmasterdan

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Seems as though changing all the sensors and reluctor wheel might be a wee bit spendy. So if you have a gen 3 car ,in my case a 2000 Vette are the ls6 blocks just as good as the G block? I plan on changing the piston's and rods and adding an f1.

Dec 10, 2017 | 11:28 AM

G Atsma

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From: Central Cal.

There is no "G" block . He was referring to me, G Atsma.
But yeah, the LS6 block is very good if you can find one.

Dec 10, 2017 | 09:24 PM

sillysspeed

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Fish master Dan where are you located?

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Dec 11, 2017 | 07:07 AM

sillysspeed

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From: MD

Quote:

Originally Posted by Fishmasterdan

The great PNW . Almost to Canada.

That's fitting of you screen name lol. Always wanted to visit out there. Reason I was asking I have a ls6 block and would like a aluminum 5.3 but we are too far away.