LQ4 heads, cast iron vs. aluminum

Discussion in 'High Tech Retrofits' started by Paul1979, Sep 12, 2011.

  1. Paul1979

    Paul1979 Veteran Member

    Messages:
    402
    Likes Received:
    1
    Joined:
    Oct 10, 2007
    Location:
    Treasure Valley
    Aside from weight and heat transfer, is there any difference between the '99-'00 cast iron heads versus the later aluminum version? My internet research seems to indicate the only reason for the increase in power of the Generation III LQ4 over the years is due to different cam, not the heads.

    Reason I ask is the local junkyard has several running LQ4's but the aluminum headed ones are $200 more.
     
  2. usmcz28

    usmcz28 Veteran Member Lifetime Gold Member

    Messages:
    382
    Likes Received:
    0
    Joined:
    Jun 19, 2005
    Location:
    Rochester, NY United States
    Are they 317 heads? They swapped over to Aluminum but I want to say they also did something with the cam shaft as well. If you check on LS1tech you can find the heads pretty cheap even with shipping. If you spend any more than $400 keep looking through LS1tech and yous hould be able to find some 243 heads off of an LS6 for a decent price.

    I sold my 317 heads locally for $200 and a set of 243's for $450 locally too. Keep looking, i'd definately want some aluminum heads on my engine. I picked up a set of LS3 heads for $650 and that included the rocker arms too.



    Edit: I sold 243's not 241's
     
    Last edited: Sep 12, 2011
  3. JJFarmer

    JJFarmer Veteran Member

    Messages:
    2,447
    Likes Received:
    1
    Joined:
    Jun 28, 2002
    Location:
    Lenoir City, TN
    I think that the LS6 heads are either 243's or 799's. The 241s are LS1 heads. Me, I'd go for the weight loss and go aluminum.

    I sold my aluminum 317's for $150 shipped so there are some deals if you wait and watch LS1Tech.
     
  4. usmcz28

    usmcz28 Veteran Member Lifetime Gold Member

    Messages:
    382
    Likes Received:
    0
    Joined:
    Jun 19, 2005
    Location:
    Rochester, NY United States

    You are correct with the 241's being on LS1's and the 243's came on LS6 and LS2 engines.
     
  5. 70 gsconvt

    70 gsconvt Veteran Member

    Messages:
    1,095
    Likes Received:
    0
    Joined:
    Sep 30, 2009
    Location:
    Wadsworth, OH
    Aluminum disipates heat faster, allowing higher compression, which usually means more power.
     
  6. Air_Adam

    Air_Adam Veteran Member

    Messages:
    2,927
    Likes Received:
    0
    Joined:
    Feb 7, 2004
    Location:
    Saskatoon, SK, Canada
    Yes, but in the stock GM application, the compression ratio (as I recall) was kept the same. All else being equal, including compression ratio, the iron head would actually make more power, since it would retain combustion chamber heat better.
     
  7. Aceshigh

    Aceshigh Veteran Member Lifetime Gold Member

    Messages:
    26,757
    Likes Received:
    6
    Joined:
    Apr 9, 2001
    Location:
    Boondocks
    Almost identical head comparison in Iron VS Aluminum.

    http://www.carcraft.com/techarticles/ccrp_0602_iron_versus_aluminum_cylinder_heads_test/viewall.html

    PRO's = Aluminum is lighter and dissipates heat faster, that's the gist of it.
     
  8. mrvedit

    mrvedit Veteran Member

    Messages:
    1,355
    Likes Received:
    4
    Joined:
    Jun 12, 2009
    Location:
    Ann Arbor, MI
    Considering all the time, money and effort you will put into the LS swap, I'm confident you would later regret not getting the Aluminum heads. Even if there is little performance difference, they are lighter and "cooler" (in more ways than one).
     
  9. ProStreet78z28

    ProStreet78z28 Banned

    Messages:
    784
    Likes Received:
    1
    Joined:
    Feb 19, 2011
    Location:
    In Transit to California


    If you have ever messed with aluminum heads, you quickly realize when people say they are lighter, they is a significantly lighter! We are talking more than a few pounds here...
     
  10. Aceshigh

    Aceshigh Veteran Member Lifetime Gold Member

    Messages:
    26,757
    Likes Received:
    6
    Joined:
    Apr 9, 2001
    Location:
    Boondocks
    Last edited: Sep 29, 2011

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.