243 casting heads on 5.3 has anyone done this
Aug 12, 2007 | 12:41 AM
#1
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From: La Mesa/Pomona
243 casting heads on 5.3 has anyone done this
I gotta set of 243 heads wanted to know whats required to put them on I hear that they have to milled at least .030 is that true? and do I need to get new push rods and lifters and rocker arms or can I used my rocker arms and lifters and push rods from my 5.3 heads? is there anyone with this set up?
Aug 12, 2007 | 01:04 AM
#2
Thinking about LS6 heads and TR220 in my 5.3.
I started the thread above awhile back, it should have all the info you need. By the way, you will actually lose power if you just bolt 243's on a 5.3 without milling them down to at least 9:1 cr, imo i would go 10.5:1-11:1. they have bigger combustion chambers meant for larger displacement engines.
I started the thread above awhile back, it should have all the info you need. By the way, you will actually lose power if you just bolt 243's on a 5.3 without milling them down to at least 9:1 cr, imo i would go 10.5:1-11:1. they have bigger combustion chambers meant for larger displacement engines.
Aug 12, 2007 | 08:47 AM
#4
THis has been discussed quite a few times recently.
The combustion chamber on the 243's are ~64cc and will reduce your compression ratio if you swap onto a 5.3 LM7. Yes with milling you can bring the CR back up and then you will need the shorter pushrods.
Some 5.3's like the L33 come with flat top pistons and 799/243 heads but because the volume of gas is decreased with the flat pistons the CR ends up at 9.9:1
Do a search, there is a long thread from last week about this.
Edit: https://www.performancetrucks.net/fo...heads+on+a+5.3
read that ^^
The combustion chamber on the 243's are ~64cc and will reduce your compression ratio if you swap onto a 5.3 LM7. Yes with milling you can bring the CR back up and then you will need the shorter pushrods.
Some 5.3's like the L33 come with flat top pistons and 799/243 heads but because the volume of gas is decreased with the flat pistons the CR ends up at 9.9:1
Do a search, there is a long thread from last week about this.
Edit: https://www.performancetrucks.net/fo...heads+on+a+5.3
read that ^^
Aug 12, 2007 | 03:38 PM
#5
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From: Houma, LA
My old man just bought an `07 Sierra, well.....it would seem as though he bought it for my mom. The ******* **** won' t let him drive the only new vehicle he ever bought for himself. Anyway, I don' t know much about it, which is while I' ll be around for a while. However his truck did came with the 5.3 with DOD, and it already has the 243 heads on it. Is this a new change for `07, or are they standard on the DOD motors? 
Aug 13, 2007 | 12:51 AM
#6
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From: mexico
Originally Posted by Darth Z
My old man just bought an `07 Sierra, well.....it would seem as though he bought it for my mom. The ******* **** won' t let him drive the only new vehicle he ever bought for himself. Anyway, I don' t know much about it, which is while I' ll be around for a while. However his truck did came with the 5.3 with DOD, and it already has the 243 heads on it. Is this a new change for `07, or are they standard on the DOD motors?
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Aug 13, 2007 | 01:08 AM
#8
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From: mexico
Originally Posted by Darth Z
Hmmm, I wonder if I can swap them onto the LS6 block in my Z, without my old man noticing?!?!
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