Differences in 5.3 block castings
On The Tree
Joined: Nov 2015
Posts: 142
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What are the bigger CI guys doing for aluminum blocks?
Im gearing up for a new chassis and im now concerned about weight. My current setup is a iron 6.0l that has been a champ but now i wanna loose as much weight as possible.
What are my options for a strong aluminum 6.0 block
Im gearing up for a new chassis and im now concerned about weight. My current setup is a iron 6.0l that has been a champ but now i wanna loose as much weight as possible.
What are my options for a strong aluminum 6.0 block
Lead.
Edit, just do a few searches....
https://ls1tech.com/forums/generatio...5-3-block.html
The info is out there.
I have doubts that there are any differences in gen IV 5.3L aluminum block castings. It seems too costly to cast different designs for similar applications with no real performance gain or loss in stock trims.
What I dug up is gen IV aluminum 5.3 RPO's are; LH6, LH8, LH9, and LC9
The differences between those blocks is variations with flex fuel, VVT, and AFM but all aluminum 5.3 gen IV blocks. My guess is, the blocks are all the same but as of today its only a guess.
So anyone pulling from yards can you update this thread what you discover? We owe it to ourselves to save the good stuff
What I dug up is gen IV aluminum 5.3 RPO's are; LH6, LH8, LH9, and LC9
The differences between those blocks is variations with flex fuel, VVT, and AFM but all aluminum 5.3 gen IV blocks. My guess is, the blocks are all the same but as of today its only a guess.
So anyone pulling from yards can you update this thread what you discover? We owe it to ourselves to save the good stuff
In my experience no thats not the case at all. IIRC there were at least 7 casting numbers for the original 346 aluminum LS1 before the LS6 block arrived and they were all of the same design more or less. Certainly nothing as radical as siamesed cylinders. Maybe some windage or oiling passage changes but thats drawing on old memories. Heads its much easier;
853/241 head? Same. Different casting process, but same casting. 862/706? Same. 4.8L/5/3L iron blocks? All but a few are the same and I dont know how many different casting numbers there were over the years but there were certainly more than 1.
243/799 head? Same, and VERY similar to 317 which has larger chambers but same port
etc.
The design upgrades ( or sometimes downgrades 010 block etc ) more often than not go across the board in GM applications.
853/241 head? Same. Different casting process, but same casting. 862/706? Same. 4.8L/5/3L iron blocks? All but a few are the same and I dont know how many different casting numbers there were over the years but there were certainly more than 1.
243/799 head? Same, and VERY similar to 317 which has larger chambers but same port
etc.
The design upgrades ( or sometimes downgrades 010 block etc ) more often than not go across the board in GM applications.
Cast iron. Far as I know its same block as the LM7 with the addition of AFM. IIRC there is one special iron block that you can identify by the casting indicators of all three sizes; 4.8, 5.3, + 6.0L vs the regular iron blocks which show 4.8 + 5.3 together or 6.0L on its own. It might be siamesed bore, theres something about it more awesomer apparently.
Plenty of LM7 builds out there making major power so I wouldnt hesitate to run an LY5 although id surely ditch the AFM for performance use its meh. AFM blocks are easy to spot because they have pedestals under the valley cover that really need to be plugged up if your deleting AFM to keep the oil from blowing out of them.
Plenty of LM7 builds out there making major power so I wouldnt hesitate to run an LY5 although id surely ditch the AFM for performance use its meh. AFM blocks are easy to spot because they have pedestals under the valley cover that really need to be plugged up if your deleting AFM to keep the oil from blowing out of them.
Last edited by cam; Nov 12, 2017 at 06:34 AM.
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