5.3l heads on ls1
03-29-2014, 09:08 AM
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5.3l heads on ls1 I'm kinda newer to the ls1 but have been reading up on what heads are recommended. I see the 243s are wat most people go with. I was thinking of snagging some cheap heads off a 5.3 for my ls1. A course I'd have them p&p , valve job, etc. but my real question is, what year 5.3l heads work? Are they all the same throughout the years or are newer ones better?? What's the casting number?? I haven't done much research but I know some one here knows . Thanks in advance !!
03-29-2014, 12:08 PM
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03-29-2014, 12:37 PM
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Thanks for the response!! I just bought my first ls1 f body, so far I got a lid, lt headers, ORY and a cut out. I'm looking to do heads and a cam but still be able to DD . I'm trying to do a budget build and figured since 5.3 heads can be had for so cheap y not look into it.
03-29-2014, 12:40 PM
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03-29-2014, 03:07 PM
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I picked up what I thought was an LH6 engine (supposedly first gen IV with all aluminum block). However, looks like it doesn't have the active fuel management, and the pistons have a slight recess, so I'm not sure what it is. The garage I bought it from said it came out of an '05 Trailblazer, and that the 8th VIN digit was "M". That makes it an LH6, unless there was some transition engine between the Gen III and Gen IV that's not well documented. Anyway, it has the 862 casting heads. I'm putting a turbo on it, and am trying to figure out what to do with cam/heads. Sounds like I might shave the heads to bring up the compression a bit (I'm guessing it's the lower compression pistons), but wondering if I'll go oversize for the valves. Any suggestions on these heads?
Last edited by jtomasik; 03-29-2014 at 03:20 PM.
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03-29-2014, 03:16 PM
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I'm kinda newer to the ls1 but have been reading up on what heads are recommended. I see the 243s are wat most people go with. I was thinking of snagging some cheap heads off a 5.3 for my ls1. A course I'd have them p&p , valve job, etc. but my real question is, what year 5.3l heads work? Are they all the same throughout the years or are newer ones better?? What's the casting number?? I haven't done much research but I know some one here knows . Thanks in advance !!
1) Castech castings were known to crack around some of the head bolt holes. They can be identified by the battery logo in the rocker arm area. They can be either the 862 or 706 casting numbers.
2) The older heads have a void in the deck. This doesn't make them unusable, but you can't use the typical MLS head gasket with them or else they'll leak water. These can all be either 862 or 706 castings.
03-30-2014, 08:48 AM
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There are two things to look out for with the 5.3L heads:
1) Castech castings were known to crack around some of the head bolt holes. They can be identified by the battery logo in the rocker arm area. They can be either the 862 or 706 casting numbers.
2) The older heads have a void in the deck. This doesn't make them unusable, but you can't use the typical MLS head gasket with them or else they'll leak water. These can all be either 862 or 706 castings.
1) Castech castings were known to crack around some of the head bolt holes. They can be identified by the battery logo in the rocker arm area. They can be either the 862 or 706 casting numbers.
2) The older heads have a void in the deck. This doesn't make them unusable, but you can't use the typical MLS head gasket with them or else they'll leak water. These can all be either 862 or 706 castings.
Hmm....first time I heard the 862's could've had cracking issues. I checked mine (they're 862's), and I don't see the battery logo. All that's on there is that production shift clock, and a number. Battery logo? Kinda confused....
