GM B-Body Forum, 77-79 Caprice/Impala Forum

Join Now If Your A 1977- 1979 Caprice or Impala owner or other GM B-Body owner!!!
Like us on Facebook https://www.facebook.com/BBodyForum?ref=hl

Join the forum, it's quick and easy

GM B-Body Forum, 77-79 Caprice/Impala Forum

Join Now If Your A 1977- 1979 Caprice or Impala owner or other GM B-Body owner!!!
Like us on Facebook https://www.facebook.com/BBodyForum?ref=hl

GM B-Body Forum, 77-79 Caprice/Impala Forum

Would you like to react to this message? Create an account in a few clicks or log in to continue.
GM B-Body Forum, 77-79 Caprice/Impala Forum

A forum for the owners and enthusiasts of General Motors B-Bodies from 1977-1990, but dedicated to the owners of 1977-1979 Impalas and Caprices. Join up now!


2 posters

    L98 Aluminum heads

    terry cronk
    terry cronk
    Freshman Member (Tier 3)
    Freshman Member (Tier 3)
    5th Year Anniversary
    Celebrating 5 years of being our member!


    Posts : 249
    Join date : 2015-08-19
    Age : 76
    Location : Mid-Michigan

    L98 Aluminum heads Empty L98 Aluminum heads

    Post  terry cronk Wed Aug 26, 2015 2:29 pm

    I purchased a set of aluminum heads this spring. They came from the 1987-90 Corvettes.

    I was told they had been given a new grind. I proceeded to tear down and found the seals were cracked and not good.

    So I did a valve grind and seat job on the heads. New pressed on seals w/o-ring on the stem.

    I replaced the valve springs with Z28 springs(1.25 outside dia.), keepers and retainers. Good for .525 lift. Some claim .550.

    Before hand I did a little port match to the intake gasket. And a small amount of blending the exhaust port below the valve seats.

    The heads only have 1.94/1.55 valves. A good low rpm, higher torque head.

    All that will go on a basic stock 350 I have. Re-ring, Check the bearings(rod and crank), replace if needed.

    I purchased an Edelbrock intake #2701, Edelbrock #1405(600cfm)carb.

    I will put in the Comps cam #12-238-2. It has a 262/270 duration w/.462-.469 lift. A good 5500 rpm range.

    That will be my install into my 79 Caprice this winter. Along with a rebuilt turbo 350 w/shift kit.

    Right now I have the 3.08 gears. Hoping to go either 3.55 or 3.73 posi.

    Any comments as to the choices?



    terry cronk
    terry cronk
    Freshman Member (Tier 3)
    Freshman Member (Tier 3)
    5th Year Anniversary
    Celebrating 5 years of being our member!


    Posts : 249
    Join date : 2015-08-19
    Age : 76
    Location : Mid-Michigan

    L98 Aluminum heads Empty L98 Aluminum heads

    Post  terry cronk Thu Aug 27, 2015 11:46 am

    I haven't totaled it up as yet.  But I will be weighing the heads, intake and water pump altogether of both the cast iron and the aluminum.

    I am think at least a 70-80# weight reduction on the front end.

    Any guesses?

    I for got to add the shorty headers. Removing the cast iron should be another 8-10# off.
    GM B-Body Forum
    GM B-Body Forum
    Admin
    Admin
    Helpful and Responsive Member!
    Very active with responding and helping other members with questions and concerns.
    10th Year Anniversary
    10 years of being a member on our forum!


    Posts : 755
    Join date : 2013-01-14
    Age : 31
    Location : Flint/Detroit, MI - Charlotte, NC

    L98 Aluminum heads Empty Re: L98 Aluminum heads

    Post  GM B-Body Forum Fri Aug 28, 2015 11:43 am

    Id go with a 3.73 but thats because thats what im going with, i dont drive the car very much so the 3.73 will just make it a more fun car!
    This is the project i did with mine that i finished earlier this year, the car itself will never be finished since having a project car is never ending. My cam is very similar but im thinking of putting a bigger one in since my application needs it and can handle it. I would have loved to put aluminum heads on but since my bottom end is stock i didnt feel it was worth it to take advantage of the extra compression and power i could get but id have to put new pistons and had the block machined, so i kept it cheap, and so far so happy.
    https://www.gmbbodyforum.com/t281-vortec-head-350-project-build


    Last edited by GM B-Body Forum on Fri Aug 28, 2015 11:51 pm; edited 1 time in total
    GM B-Body Forum
    GM B-Body Forum
    Admin
    Admin
    Helpful and Responsive Member!
    Very active with responding and helping other members with questions and concerns.
    10th Year Anniversary
    10 years of being a member on our forum!


    Posts : 755
    Join date : 2013-01-14
    Age : 31
    Location : Flint/Detroit, MI - Charlotte, NC

    L98 Aluminum heads Empty Re: L98 Aluminum heads

    Post  GM B-Body Forum Fri Aug 28, 2015 11:50 am

    I know stock smog iron heads weigh in at about 50lbs each fully assembled. heres a post of some weights https://www.gmbbodyforum.com/t307-gen-1-sbc-weights-aluminum-vs-iron#2972
    terry cronk
    terry cronk
    Freshman Member (Tier 3)
    Freshman Member (Tier 3)
    5th Year Anniversary
    Celebrating 5 years of being our member!


    Posts : 249
    Join date : 2015-08-19
    Age : 76
    Location : Mid-Michigan

    L98 Aluminum heads Empty L98 aluminum heads

    Post  terry cronk Fri Aug 28, 2015 9:20 pm

    Thanks for the weight comparisons.

    The 350 motor I am going to tear down is a lower compression boat motor.

    So the 58cc heads will help the compression. Vortec heads are like 62cc?

    With the B.O.P. axle it should be fine with 3.73.

    I will soon know what is what when the cover comes of.

    Thanks
    GM B-Body Forum
    GM B-Body Forum
    Admin
    Admin
    Helpful and Responsive Member!
    Very active with responding and helping other members with questions and concerns.
    10th Year Anniversary
    10 years of being a member on our forum!


    Posts : 755
    Join date : 2013-01-14
    Age : 31
    Location : Flint/Detroit, MI - Charlotte, NC

    L98 Aluminum heads Empty Re: L98 Aluminum heads

    Post  GM B-Body Forum Sat Aug 29, 2015 12:15 am

    Stock vortecs are 64 but i had mine shaved to 62cc and im using steel shim .015" head gaskets, trying to squeeze all the compression i can get, but with your 58cc you can use the standard .041" headgaskets and compression should be real good.

    Sponsored content


    L98 Aluminum heads Empty Re: L98 Aluminum heads

    Post  Sponsored content


      Current date/time is Tue May 07, 2024 12:55 am