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which head to use.

Discussion in 'Engine & Performance' started by seniorbear69, Apr 7, 2021.

  1. seniorbear69

    seniorbear69 Member

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    HI all sum advice required im having to replace the heads on my 84 c20 i have a choice of three difrent casting # 882 /810 /or 187 itsa shame as im having to junk a pair of vortecs as thay are craked .that is whot i have so it hs to be one of the casting # thay are going on top of a 350 with flat tops and 4 valve relifes .
     
  2. yevgenievich

    yevgenievich Full Access Member

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    882 if it is not the light casting would be my guess
     
  3. BillK

    BillK Junior Member

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    Just curious . . . where are they cracked ?
     
  4. ali_c20

    ali_c20 Full Access Member

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  5. seniorbear69

    seniorbear69 Member

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    the head has cracked acros the top from the rocker stud ill try post a pick .yepi know the others are bad compeard to the vortec but at the moment after this covid mess work has been on its ass so have to make do with whot i have .yes back to the old twelve bolt manifold .
     
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  6. Bextreme04

    Bextreme04 Full Access Member

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    I'll be using 882's on my mild build. They seem to be a decent head, but did you build your current motor with the intention of running the small chamber vortecs? If so, you are going to have some really bad compression numbers with the large chamber 882's. I've designed mine to be around 9.00:1 static and a little over 8.1:1 dynamic compression with a solid .045" quench. If you have designed your motor to have good compression/quench numbers with a vortec head, you are going to have a bad day with standard large chamber heads, which is what the 882 heads are with a 76cc chamber. The 187's are early camel humps and will have the same small chamber as your Vortec's, but probably don't have hardened seats for unleaded gas. The 810's should be a small chamber TBi head and would be a good choice for a tow rig. I'd be worried that you'll burn a valve seat if you will be pulling heavy loads or towing with the 187's. If you are in a lighter truck and just ripping around the streets, the 187 is probably a better overall head than the 810.

    How did the heads you are currently running crack? What was your static and dynamic compression with the vortecs and current cam? What head gasket and compressed thickness were you running and what was the deck height and quench?
     
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  7. seniorbear69

    seniorbear69 Member

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    well thank you or yore help .but the head craked around no 3 inlet rocker stud in 2 places and the std moved .peces of the head droped into the intake port and into the cylinder beat the piston up and put a 3/8 gouge down the bore .so for know the 350 is toast and the vortec head had been messed with with screw in studs fitted .weater thay wer no fitted properly weather the head being a ex marine piece was roted out and thin in this area i dont know ,stock springs and cam so nothing the head should not of been able to cope with .ive just picked up a 305 which is making its way in the bay to keep me mobile whilst i sort sumint out with the mess of a 350 i have .
     
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  8. K5ride

    K5ride Member

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    I'm going through the votec cracked head issue now. I picked up an L31 Vortec that was running good and thought I would build it. When I took the heads to the machine shop, I found out they were both cracked. The machinist said about 9 out of 10 Vortecs he sees in his shop are cracked. I found some Vortec heads at Summit Racing (SUM-151124) that use stronger alloy and are thicker to avoid cracking. They have the screw in studs, Comp Cams 81-16 springs and already have the stem seals lowered to accept larger lift cams. They are priced good compared to the cost of doing these upgrades to a set of heads. I paid about $360 a head, ready to install. I was told they are made by Dart. The slight differences I saw were the Summit heads have a little larger intake volume (175cc compared to 170cc) and the chamber size is slightly larger (67cc compared to 64cc). They appear to be well made and clean. Porting looks good too.
     
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  9. seniorbear69

    seniorbear69 Member

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    thanks thats interesting .i now belive if you want vortec heads pick up new ones or you are on a road to disapointment and cost this cost me an engine ok it can be rebuilt but at a cost .thanks to every one for yore help .steve
     
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  10. Catbox

    Catbox Full Access Member

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    For Vortec stuff, I have been watching what this feller has been putting out.
    His YouTube is called Piss-Cutter Performance.
    He has lots of interesting stuff to view.

     
  11. seniorbear69

    seniorbear69 Member

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    WOW thats great i like that kit wonder if its avalable hear in the uk
     
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  12. Catbox

    Catbox Full Access Member

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    I know I will be ordering the kit one of these days as I have a set of Vortec junkyard heads out in the garage.
    Who knows if they are cracked or not.
     
  13. 82sbshortbed

    82sbshortbed Fuckemall!!

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    I found the little head gets you in trouble more often than your big head. Lol
     
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  14. Bextreme04

    Bextreme04 Full Access Member

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    You have vortec SBC heads too?? I thought you had all the big blocks now :burnout:
     
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  15. Catbox

    Catbox Full Access Member

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    I am a parts whore.

    I have 5 or 6 sets of small block heads here.
    3 sets of big block heads.
    4 sets of VW heads, one of which I can sell and but a set of aluminum big block heads.
    Damn things are spendy.

    I have complete engines in each size as well.
    It is amazing how well I can hide stuff from my wife...
     

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