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.

1988 TBI setup on non vortec heads HELP

Discussion in 'The Garage' started by 74Jimmy, Jul 28, 2003.

  1. 74Jimmy

    74Jimmy Registered Member

    Joined:
    Mar 2, 2002
    Posts:
    16
    Likes Received:
    0
    Location:
    Corpus Christi, Tx
    I know somebody out there has hogged out the center holes on the new intake to fit on the old heads. Does anyone have a picture of the completed intake? Is that the only modification that has to be done to make it work? Does the intake seal properly?

    Thanks /forums/images/graemlins/k5.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif
     
  2. Chris Demartini

    Chris Demartini 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    2,406
    Likes Received:
    1
    Location:
    Dumont NJ 07628
    <font color="blue">An 88 TBI setup never came on Vortec heads. What heads are you using?
     
  3. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    I think he just means on non 4 bolt valve cover heads. There is a guy selling a motor out of like an 89 Caprice on Ebay as a Vortech motor with TBI. I informed him he was quite inncorrect in his information. I hate when people do that.
     
  4. 89K1500Chevy

    89K1500Chevy 1/2 ton status

    Joined:
    Nov 9, 2002
    Posts:
    645
    Likes Received:
    0
    Location:
    Georgia, Fayetteville
    It can be done....Like he said you have to drill the holes on the intake to an angle but i havent done it or seen them done But i do know that it is possible. also you can buy vortech heads for TBI now from GM perfromance parts for like 250 a head. I think they even have a newer style intake for it as well.....
     
  5. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    yes they sell a newer intake so if you put vortec heads on a sbc you can use their TBI intake. Also I know its very doable to put the TBI intake and unit on an older style vehicle but you know he may be better off buying a cheap old style performance manifold and using a TBI ADaptor plate. You have to drill and tap vaccum stuff for the MAP sensor and similar and throttle linkage has to be custom but it would probably perform better than the stock unit.
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,980
    Likes Received:
    189
    Location:
    Roy WA
    Were there any stock TBI intakes made pre-centerbolt?

    I know there were for TPI, never heard of it for TBI.

    Figure that would be a decent option if they are out there.
     
  7. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    I don't believe so, TBI engines were built earlier than 87 in Camaros and Firebirds but I am not certain if they had centerbolt heads or not. I think so. Drilling the holes isn't difficult that searching out the new intake if you have one would be kind of a waste.
     
  8. bowtiepower00

    bowtiepower00 1/2 ton status

    Joined:
    May 11, 2000
    Posts:
    924
    Likes Received:
    0
    Location:
    AZ
    The question refers to NON-Vortec heads, correct? If so, the only difference is the angle of the inside bolt holes and can be fixed relatively easily. I believe that you can buy spacers specifically for that purpose (check summit). If you are talking about Vortec heads, the intake face is completely different, and although the vortec heads can be modified to fit a non-vortec manifold, you will run into vaccuum leaks. To the best of my knowledge, 87 was the first year for the V8 TBI motor (earlier crossfire motors excluded) The TBI manifolds flow like crap, use a holley 4bbl adapter, ditch the EGR, and slap the Throttle body on a good early style manifold.
     
  9. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    thats what i say, tbi heads and intakes are BIG bottlenecks on the motors.
     
  10. 74Jimmy

    74Jimmy Registered Member

    Joined:
    Mar 2, 2002
    Posts:
    16
    Likes Received:
    0
    Location:
    Corpus Christi, Tx
    Yes everyone these are non-vortec heads with an 1988 TBI setup which as I see above did not come with vortec heads just the center bolt valve covers and a different angle on the middle 4 bolts. Bowtie you say use an old style 4 bbl manifold with adapter but as has been said above there is alot of drilling and tapping that needs to be done to get the sensors hooked up. Here's the deal fella's I'm a poor government employee that get's a $10.00 a week allowance from the wife for my project. So what I have right now is a 85% complete TBI setup (manifold, throttle body, wiring harness, computer, distributor, coil,and all the sensors that go into the manifold)It is going onto an ATK 275HP 350 that is about a year old, I am probably going to have to change the cam to something with a little lift/duration. So the cheapest and easiest way I can get this ontop of the motor hooked up and running the better. I know that is really not the right way to do it but you gotta do what you gotta do right. I have seen posts about a book called TBI swappers guide but it is out of print and I have been unable to locate it as of yet. If someone out there knows of where I can get a copy please let me know. Again thanks for all the good info. /forums/images/graemlins/k5.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif
     
  11. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,980
    Likes Received:
    189
    Location:
    Roy WA
    Did you try searching on here for the bolt hole hogging out idea?

    thirdgen.org has a TBI forum IIRC, yu can maybe find some info there.

    I've seen pictures of a newer intake setup for the "old" style intake bolt pattern, and I think it just entails grinding the horizontal surfaces to a 45* angle, and matching the bolts up. Probably the most important thing is, that the surface needs to be flat, and as thick as possible, because the AL might crack if it's not "perfect".

    I am 99% sure there is no difference in the water passages or intake port on the heads to worry about when changing from the "old style" to "new style" intake. Vortecs are one of the few that have the "raised intake port" design, which is why even a set of drilled vortec heads can't take an earlier intake.
     
  12. Bushwhacker

    Bushwhacker 1/2 ton status GMOTM Winner

    Joined:
    May 13, 2002
    Posts:
    796
    Likes Received:
    0
    Location:
    Indian Trail,North Carolina
    I put TBI from a 88 Blazer on my truck. I used a Edelbrock TBI intake and had to grind the center bolt holes to bolt on to my pre 86 style World heads. No problems, sealed fine and works like a dream. /forums/images/graemlins/wink.gif

    Clay
    /forums/images/graemlins/usaflag.gif /forums/images/graemlins/truck.gif
     

Share This Page