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Thread: Heads question

  1. #1
    Join Date
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    Heads question

    Running 4.8. Would a head swap give me any extra HP. I don't know all the different castings. A clear response on the differnt castings and what could be expected from each would be very appriciated. Only other thing i plan to do is a cam if that makes a difference. NO boost or spray. Thanks guys.
    Last edited by tanz45; 11-17-2008 at 11:11 AM.
    2013 CC 5.3
    81 C10 LS1 project

  2. #2
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    u can get prc 5.3 heads with cam of you choice form texas speed and performance for about 2,000 comes with new gaskets and head bolts springs push rods and timing chain and oil pump if you want PRC 220cc 5.3L Stage 2.5 CNC Ported Heads
    74 Austin Morris Mini 1000 - Daily Coil Spring conversion, lowered, Disc Brake conversion
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  3. #3
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    Doing some looking. The ls6 243 heads with 64.4 combustion chamber, will bold to a 4.8? If they do, can they be milled down to the 4.8 61mm combustion chamber size for same cr?

    I'm going off the fact of being able to get a set for cheap, if I can even find any

    Would it even do any good?
    Last edited by mnc2fan; 12-23-2008 at 02:45 AM.
    - Waiting for an lq9 swap - Super 40 center in dual out - battery swap to spare tire location - exhaust turndown -

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  4. #4
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    those PRC heads are good, i want to get me a set of em.....

  5. #5
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    Quote Originally Posted by mnc2fan View Post
    Doing some looking. The ls6 243 heads with 64.4 combustion chamber, will bold to a 4.8? If they do, can they be milled down to the 4.8 61mm combustion chamber size for same cr?

    I'm going off the fact of being able to get a set for cheap, if I can even find any

    Would it even do any good?
    Yes, they flow about 20cfm better, and can be milled about .020 to drop cc's to about 61. Just check manifold fitment when reinstalling.

    1993 Gmc 02 ls1 Circle D 3400 stall, long tubes, 220/224 cam stage 3 heads, weiand intake, auburn posi, 389rwhp 352ft/lbs

  6. #6
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    Quote Originally Posted by Turbo_smh View Post
    Yes, they flow about 20cfm better, and can be milled about .020 to drop cc's to about 61. Just check manifold fitment when reinstalling.
    Compared to prc head for the 5.3 do they flow better?
    - Waiting for an lq9 swap - Super 40 center in dual out - battery swap to spare tire location - exhaust turndown -

    2

  7. #7
    Join Date
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    Del Rio, TX
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    Well the PRC's sound like a better head although you can port the ls6's to flow more. My best friend got 308cfm out of my 853 castings which were originally CNC'd by Patriot to only 278cfm who claimed 290. Im skeptical with going with a company after we went through and fixed a lot of flaws with mine. You may even come out cheaper also

    1993 Gmc 02 ls1 Circle D 3400 stall, long tubes, 220/224 cam stage 3 heads, weiand intake, auburn posi, 389rwhp 352ft/lbs

  8. #8
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    Curious to know if the 862s from '99-'04 were different from the 706s that were found on '04s. I haven't found any data that states anything better/worse on either.
    Test-n-Tune (Nov 23, 2008) - 13.65s @ 98mph

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