5.3 chevy LS heads 862 to 241 Casting - JeepForum.com
 
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post #1 of 10 Old 03-08-2013, 06:48 PM Thread Starter
Cajun90YJ
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5.3 chevy LS heads 862 to 241 Casting

I recently completed my 5.3 swap in my 90 wrangler, long story short I have a bad valve on cyl #8 low compression. So I was intent on having them rebuilt and called my machine shop, machine shop says he has a set rebuilt someone left and never came back to get, for the same price as having mine rebuilt. So I figure I will just buy them and bolt them on with no wait. Well I get them home and look up the casting number to find out they are 5.7 heads with 2.00 intake valves. My question is will I need to change injectors with these heads or will the 5.3 injctors work, also what head gaskets should I use camero 5.7 headgaskets or 5.3 headgaskets. I'm thinking 5.3 head gaskets. these should boost my compression to 10.1 to 1 I think. here is info on the two heads
http://www.performancetrucks.net/for...g-info-434396/

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post #2 of 10 Old 03-10-2013, 08:21 AM Thread Starter
Cajun90YJ
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Ok I did some more searching and found out that the 241 heads were run with flat top pistons and the 5.3L did not come with flat top pistons until 2004. Mine is a 1999 so it has reccessed pistons, so if I were to install the 241 heads with reccessed pistons it would cause my compression ratio to drop thus losing power. It is possible to mill the 241 heads to decrease the combustion chamber size and regain the compression but I dont really want to do that. Looks like I will be having my truck heads rebuilt and I will put the 241 heads on a shelf for a later project.
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post #3 of 10 Old 03-10-2013, 08:38 AM
USMCBuckWild
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You would have to mill quite a bit off the head to recover the lost compression. I would rebuid the original heads, and hold onto the other ones.

91 YJ, 350/700R4/231, 8.8/HPD30 with 3.73s, 6" SOA with 38" TSLs. If I ever see the previous owner again, I am going to curb stomp that meth-head brain dead crackpot.
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post #4 of 10 Old 03-10-2013, 10:42 AM Thread Starter
Cajun90YJ
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I believe 30 to 35 thousands to regain the stock compression, I have another 5.3 in the corner for another project later on (not sure what yet) but I will likely build it with flat top pistons and use those heads. who knows but $210 for the pair, I think i'll keep em.
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post #5 of 10 Old 03-10-2013, 10:55 AM
USMCBuckWild
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I am still looking for a 6.0. I had the opportunity to pick up a complete aluminum 6.0 from a Corvette for $1000, but I hemmed and hawed for too long and missed out. How sweet would that have been? Aluminum block, aluminum headed combo in a YJ?

91 YJ, 350/700R4/231, 8.8/HPD30 with 3.73s, 6" SOA with 38" TSLs. If I ever see the previous owner again, I am going to curb stomp that meth-head brain dead crackpot.
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post #6 of 10 Old 03-10-2013, 11:02 AM
DLWRUBI
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Stock head gasket thickness is something like .055". You can get a thinner head gasket in the .030" from like Cometic. Also the rebuilt heads should have been milled down a little as well I would think.

One thing you have to check because I don't know what piston to deck height is on a 5.3L, but as long as the pistons do not come out of the hole a .030-.035" gasket should be fine.

1 point of compression is about 10 HP, howevever I thinlk the 241 heads are a better head and may be worth 10 HP over the 862's.

Also, do some research on rocker ratio, 5.3L may have been 1.7 ratio and the 5.7L may have been 1.8 ratio.

I'm sure if you hit the truck forums you'll find guys that have made the swap and find the pro's and cons of it..
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post #7 of 10 Old 03-10-2013, 11:07 AM
DLWRUBI
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Quote:
Originally Posted by USMCBuckWild View Post
I am still looking for a 6.0. I had the opportunity to pick up a complete aluminum 6.0 from a Corvette for $1000, but I hemmed and hawed for too long and missed out. How sweet would that have been? Aluminum block, aluminum headed combo in a YJ?
An LS2 6.0L would have been sweet USMC, especially at $1000, you should have jumpped in with both feet. I have a new LS3 6.2L sitting in the garage right now I'm getting ready to swap in .
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post #8 of 10 Old 03-10-2013, 11:51 AM Thread Starter
Cajun90YJ
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Quote:
Originally Posted by USMCBuckWild View Post
I am still looking for a 6.0. I had the opportunity to pick up a complete aluminum 6.0 from a Corvette for $1000, but I hemmed and hawed for too long and missed out. How sweet would that have been? Aluminum block, aluminum headed combo in a YJ?
may you gotta jump on that kind of stuff, you can always sell it later if you had too. Mega sweet!!!,
Hindsight is 20/20 they say.
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post #9 of 10 Old 03-10-2013, 11:55 AM Thread Starter
Cajun90YJ
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Quote:
Originally Posted by DLWRUBI View Post
Stock head gasket thickness is something like .055". You can get a thinner head gasket in the .030" from like Cometic. Also the rebuilt heads should have been milled down a little as well I would think.

One thing you have to check because I don't know what piston to deck height is on a 5.3L, but as long as the pistons do not come out of the hole a .030-.035" gasket should be fine.

1 point of compression is about 10 HP, howevever I thinlk the 241 heads are a better head and may be worth 10 HP over the 862's.

Also, do some research on rocker ratio, 5.3L may have been 1.7 ratio and the 5.7L may have been 1.8 ratio.

I'm sure if you hit the truck forums you'll find guys that have made the swap and find the pro's and cons of it..
That smaller head gasket would help but would still not be enough and the machine shop said only about 1.5 thousands was taken off. I probly could do it with the right combo and milling but I have not even put 100 miles on my swap so I am wanting fastest and least hassle at this point so I can drive this beast for a while. I think that would be to rebuid the stock truck heads, I know every thing will work on them. Also good point on the rockers I did not even think of that.
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post #10 of 10 Old 03-10-2013, 04:31 PM
DLWRUBI
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Gotta do what your comfort level is...Good luck.
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