Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

vortec heads

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by manyblazers, Mar 16, 2003.

  1. manyblazers

    manyblazers Registered Member

    Joined:
    Dec 13, 2002
    Posts:
    33
    Likes Received:
    0
    Location:
    toronto, Canada
    I keep reading about these 'vortec' heads. What's the deal? Are they a name only or are they different from the heads on my stock 350 from an 87 jimmy?
     
  2. Bruiser

    Bruiser 1/2 ton status

    Joined:
    May 21, 2000
    Posts:
    320
    Likes Received:
    0
    Location:
    Caldwell,Idaho
    Yes they are different , they have center bolt covers, angle of the intake to head is different, different bowl size I do beleive. The are considered better performers than stock heads.
     
  3. 88Silverado

    88Silverado 1/2 ton status

    Joined:
    Mar 13, 2003
    Posts:
    2,664
    Likes Received:
    0
    Location:
    Quartz Hill, So. Cal
    Some GM truck engines in the late 80's came with Vortec heads. These are GM factory cast which they basically used the LT-1 combustion chamber. Very good flowing heads for small valves. You can buy them for around $450-500 fully assembled from GM. They require a special intake manifold due to the bolt pattern. With some minor cleanup they can really flow.

    You can pull a valve cover off, find the number then cross-reference it on www.mortec.com to see what type they are.

    There are different opinions on weather its better to go with Vortec's and new intake or spend the extra $130 and get the World S/R Torquer which take standard manifolds and perform as good or better.

    If you go to this site http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi and do a search on Vortec, you will have hundereds of posts to review
     
  4. 84_Chevy_K10

    84_Chevy_K10 Banned

    Joined:
    May 30, 2001
    Posts:
    17,669
    Likes Received:
    0
    Location:
    IL, USA
    [ QUOTE ]
    Some GM truck engines in the late 80's came with Vortec heads.

    [/ QUOTE ]

    No Vortec heads on trucks until 1996.
     
  5. 88Silverado

    88Silverado 1/2 ton status

    Joined:
    Mar 13, 2003
    Posts:
    2,664
    Likes Received:
    0
    Location:
    Quartz Hill, So. Cal
    Your right, sorry, typo /forums/images/graemlins/blush.gif
     
  6. RootBreaker

    RootBreaker 3/4 ton status Premium Member

    Joined:
    Nov 29, 2001
    Posts:
    5,117
    Likes Received:
    173
    Location:
    Williamstown, NJ USA
    i got a 1991 Caprice 350 vortec motor with hydrollic roller lifters and cam... but that is something i will need to do... vortec heads.... they are supposedly able to gain you 30-40hp.... but dont forget that they have a different bolt pattern than the older intakes.... i took the tbi off of mine and put a 87 camaro intake on and fit like a glove.... /forums/images/graemlins/ears.gif
     
  7. Blazer_Boy

    Blazer_Boy 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    1,669
    Likes Received:
    0
    Location:
    Sioux City, IA, USA
    Careful what you read..... Every A-hole has an opnion on what they think is best. Chevy Hi-Performance was telling everyone that the 906 casting was much worse than the 802 and that they can only take .420" lift, stock. The 906 head has a harder exhaust seat and a sodium filled valve, OoOoOo, scary. Actually its the tougher truck version. The general says they'll take .475" right out of the box. I'll agree thats pushing it because I've only gotten a .480" feeler gauge in their. But as long as the lobe angles are tame enough and you don't float the valves, you'll be fine (10,000 miles with .462" exhaust lift /forums/images/graemlins/smirk.gif). They have since printed a retraction on most of the stuff they've said in that magazine /forums/images/graemlins/rotfl.gif
     
  8. Pure Insanity

    Pure Insanity 1/2 ton status

    Joined:
    Mar 17, 2001
    Posts:
    4,579
    Likes Received:
    0
    Location:
    Dade City, Florida
    Vortec heads are 96 or 7 up. I am thinking 97 up. They came on the 350 truck motors ONLY. The 305s are NOT the heads you want. Nor are any car heads, unless its a Vette or Z28. (LT1) Those are good heads also, but they are aluminum. LT4 is even better than those, but VERY hard to find used. Vette only.

    They are easily identified by the 2 end intake bolts standing straight up when mounted on a motor. The bolt holes do not come out of the head at a 90* angle like all other SBC heads. There are no center bolts for the intake, JUST the 2 on each end.

    All things being equal bolting on a set will normally net anywhere from 30-50 HP.

    You have to be careful w/ your compression ratio, IIRC the chambers are 64 or 67cc maybe.

    They require a special intake I personally run a Performer RPM Vortec. For grins and giggles I laid a regular Edel Perf. on my motor and the ports were above the intake. They SAY you can have them drilled to accept an early intake, but I would not recommend it.

    The intake gaskets needed are .120 thick IIRC.

    There is no provision for EGR.

    They require self aligning rockers.

    You can use standard SBC head bolts nothing special needed there.

    Same w/ all your accesories. Nothing special needed. (P.S. alt. A/C) I have all early stuff on mine.

    Standard SBC headers will bolt up no problem.

    And thats about all I can think of. I may have botched a few things but someone will correct me if I am wrong. Its been a while since I researched them last. Do a search of all forums and youll find a ton-o-posts about them.

    Bang for the buck they cant be beat. New in the box from GM under 5 bills, and they give great results.

    Oh and 1 last thing, I read in a GM Perf. catalog that they out flow the legendary 2.02 fuelie heads and the Bowtie heads. All heads unported comparison straight off the shelf. And finally YES they are VERY different from the heads on your Jimmy now. In comparison to Vortecs, (no offence meant to anyone), the stock 80s heads are good paperweights.
     
  9. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,975
    Likes Received:
    189
    Location:
    Roy WA
    '96+.

    Don't forget as was mentioned, any sort of higher lift cam can cause problems. I'm real close (actually have .055") to the recommended .060" clearance between retainer and seal at .452" lift. The springs on them (stock) were designed for a roller cam with about .427" max lift.

    Everything else looked good /forums/images/graemlins/smile.gif
     
  10. Pure Insanity

    Pure Insanity 1/2 ton status

    Joined:
    Mar 17, 2001
    Posts:
    4,579
    Likes Received:
    0
    Location:
    Dade City, Florida
    I always make that mistake. I dont know why I am so hung up on 97 up. /forums/images/graemlins/confused.gif

    But as I said, I may have botched something and I knew Dorian would be around to make it right. /forums/images/graemlins/rotfl.gif
     
  11. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    I don't understand why there is no EGR provision in the GM Performance Vortec heads when there is an EGR port on the Vortec style TBI intake made the same people. I will be doing this conversion over the summer in my 88' 350tbi blazer which currently has an EGR valve. How would I make the EGR system work with the Vortec setup? thanks.
     
  12. TxK5Blazer

    TxK5Blazer 1/2 ton status

    Joined:
    Aug 13, 2000
    Posts:
    593
    Likes Received:
    0
    Location:
    Floresville, Tx
    I have to intervien the late 95 models come with vortec heads too because I have on my 82 right now a set of them on a 95 model 350 and I have the center bolt valve covers and the special bolt pattern edelbrock performer vortec intake. /forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif /forums/images/graemlins/pimp1.gif
     
  13. Madbomber88

    Madbomber88 1/2 ton status

    Joined:
    Feb 7, 2001
    Posts:
    185
    Likes Received:
    0
    Location:
    Mass
    So are vortec heads really that much better than the stock heads on my 1990 K5? I'm getting a new engine soon and am debating over the heads along with everything else. Will my thorley headers on my current engine bolt right up to vortec heads?
     
  14. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,975
    Likes Received:
    189
    Location:
    Roy WA
    Would be interesting to find out if you could "open up" the EGR crossover on the Vortecs.

    One of the problems would be intake gaskets, but you'd think if someone could/did drill out the EGR crossover on Vortec heads in large quantities, there would be a large enough demand to warrant a new intake gasket to match.

    To me it doesn't look like too much work at all to take a 1" drill bit or so and go through the "pocket" where the crossover would be, but not knowing if the area is close to water passages, I wouldn't want to be the first to test it out /forums/images/graemlins/smile.gif

    www.sdpc2000.com sells a "vortec EGR adapter" for their TPI Vortec intake, probably similar/same to what you would need.

    Check into the Edelbrock Etec heads if you are thinking of new/better heads, I know they released a "new" version of them, but fast burn chambers, aluminum, and all the rest of the "performance" stuff Vortec heads generally need (including both the "old style" intake bolt pattern as well as Vortec style as well I think) in a package costing around $800 or so. Once you figure in new springs, machined valve guides for additional lift, new seals, bigger valves (if you want them) Vortec intake cost, EGR hassle, and so on, the Etecs sound pretty good. From what I recall, they had the "torquey" version of the heads, and a version for higher revving engines.
     
  15. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,975
    Likes Received:
    189
    Location:
    Roy WA
    *claims* for the Vortecs are around 30-40HP over "stock", but of course that depends on the engine they are tested on.

    They ARE that good, but they have some pretty severe limitations depending on what you want to do. In your case, you might be ok, but it depends on which engine path you choose.

    Like I mentioned in my last post, check into the Edelbrock Etecs. Dunno the cost of the GM performance parts AL fast burn heads, but you might check them out too. An "old style" bolt pattern and correct EGR crossover can save you some time/money/hassle.
     
  16. twenty_below0

    twenty_below0 1/2 ton status

    Joined:
    May 16, 2001
    Posts:
    436
    Likes Received:
    0
    Location:
    Haines, Alaska ...u.s.
    fast burns are 565.0 to 625.0 each depending on where you go but a MUCH better head , also Pro Topline or AFR makes a Vortec version but they fixed all the problems associated with the vortec and they are 650.00 assembled with the old pattern so no manifold needed , also comes with stainless valves and screw instuds etc. MUCH better deal than GM Vortecs, Go to ebay and look at engine components in the car parts section and then look at sbc heads and you'll find thesse heads and you can buy them loaded or "unloaded for 400.00" check them out they go into detail on how they improved the heads weaknesses . I'm sure if you look up these heads you'll be impressed . /forums/images/graemlins/thumb.gif
     
  17. Pure Insanity

    Pure Insanity 1/2 ton status

    Joined:
    Mar 17, 2001
    Posts:
    4,579
    Likes Received:
    0
    Location:
    Dade City, Florida
    [ QUOTE ]
    I have to intervien the late 95 models come with vortec heads too because I have on my 82 right now a set of them on a 95 model 350 and I have the center bolt valve covers and the special bolt pattern edelbrock performer vortec intake. /forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif /forums/images/graemlins/pimp1.gif

    [/ QUOTE ]Wouldnt be the first time GM or any other manufacturer either ran out of old stuff and slipped in the newer stuff early or finished up using old stuff when its "out dated". There are exceptions to almost any rule. You happened to get one of them.
     
  18. ZooMad75

    ZooMad75 1/2 ton status Premium Member GMOTM Winner

    Joined:
    Apr 5, 2003
    Posts:
    998
    Likes Received:
    592
    Location:
    Pueblo, CO
    [ QUOTE ]
    I don't understand why there is no EGR provision in the GM Performance Vortec heads when there is an EGR port on the Vortec style TBI intake made the same people. I will be doing this conversion over the summer in my 88' 350tbi blazer which currently has an EGR valve. How would I make the EGR system work with the Vortec setup? thanks.

    [/ QUOTE ]

    To Make the EGR work, you need to replicate the way that the 96 and later units run the EGR. This is done by a port off of the pass side exhaust manifold. The tube attaches to the intake just below where you bolt the EGR on. Everything works the same from there. You just need to get the pass side exhaust manifold from a dealer or boneyard and install it with the heads. Headers would require some fabrication.
     
  19. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,975
    Likes Received:
    189
    Location:
    Roy WA
    You have any pictures?

    I've got what are purportedly Vortec exhaust manifolds in my garage, and a set that are definitely off of a TBI K5, and both of them only have one "port", and both are on the drivers side. The "Vortec" manifolds have the "port" facing almost vertically, while the TBI port is basically horizontally.

    With any sort of injection that uses O2 and EGR, still going to have to work around this issue. Not real hard to weld a bung into the exhaust pipe, but still something additional.
     
  20. ZooMad75

    ZooMad75 1/2 ton status Premium Member GMOTM Winner

    Joined:
    Apr 5, 2003
    Posts:
    998
    Likes Received:
    592
    Location:
    Pueblo, CO
    I dont have pics, but if dig into my archive is should be able to dig up the part number for the vortec exhaust manifold. I'll look and post back..
     

Share This Page