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Talk slow use small words!

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by bigcountryk5, Mar 23, 2005.

  1. bigcountryk5

    bigcountryk5 1/2 ton status

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    alrighty then, i wanna wake up the old 350 in my 87K5 it's TBI and i want to get some more power out of it and want to do it myself. I wanna learn if anybodys willing to point me in the right direction.

    For starters every one seems to really like chevy's vortec heads and this seems to be a fairly common upgrade.....

    So my question is what makes them so great, what does the swap to vortec heads do for you (the advantages), and would it be possible for me to do it myself (note: little mechanical knowledge but if i do my research and have the proper tools and some patience could i pull it off?)

    I've got about a hundred other questions but i'll see if i get any bites on this one and annoy you with the rest latter;)
     
  2. k20

    k20 3/4 ton status

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  3. personaltrainer

    personaltrainer 1/2 ton status

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    don't know much about the swap - but pulling the heads isn't that difficult. did it first time about 4 months ago. I'm like you, did my research, went to sears and bought a bunch of craftsman stuff and got to work. I can tell you that quality tools will certainly make your job go more smoothly.

    good luck, keep us posted.
     
  4. MarcS

    MarcS 1/2 ton status

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    Get yourself a How to Build a Chevy Small Block book or Chevy SB Performance book. They are usually filled with great info on modifing SB's in plain simple English. Look for them at Summit, Jegs, Amazon etc....
     
  5. the beast

    the beast 1/2 ton status

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    X2.... should be in every Bowtie guys shop...:D
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    I agree with everything in that article. One thing I didn't see covered is TBI/TPI, which causes an expensive problem with Vortecs, or at least requires more money. Intake manifold and EGR. Can't run EGR like your TBI setup, so not going to be smog legal if you just get a Vortec carb manifold and adapt it. If you buy the expensive TBI intake, you can run EGR, but that is even more money as you have to buy the pieces to route it.

    I knew the cost would be comparable, throw in the $250 or so TBI intake +EGR stuff and the Trick Flows would be cheaper.

    One point made was the Vortec combustion chamber. I have no idea why the aftermarket seems slow to adapt that, but the fast burn combustion chamber is one of the reasons the Vortec heads are so great. If you can find aftermarket heads that will take your stock intake, stock EGR routing, and have a fastburn chamber, you'd have some real good heads.

    Not trying to get into big words, but to make the most of the swap, getting into PROM tuning is a necessity to get the most out of your setup when it's modified, and someone on here netted better MPG by *just* modifying the stock calibration. If intent on increasing TBI power, you may want to start with PROM tuning stuff first.
     
  7. 87BrnRsd

    87BrnRsd 1/2 ton status

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    Try checking out www.cfm-tech.com They have a ton of useful tuning info and sell some really good power adding parts. I highly recommend their "tbi power package" Its easy to install, and offers a lot of bang for the buck. After that I would add a good set of headers, and true duals. Then get a custom chip burnt and your engine will run like it never has before.
    -Harrison
     
  8. Supergas

    Supergas 1/2 ton status

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    Simple TBI Performance

    I am in the process of finally building my new engine after the same dilemma that you are in...

    I have decided to save some money & NOT go the 383 route. I have a freshly bored block (.030 over) & a good crank, rods, pistons etc... so I am going to be content with a 355. ( I ran a 355 in NHRA super street for 10 years so I know what kind of all out performance can be had)

    With that said, I decided NOT to use the Vortec heads as the intake manifold is $325.. instead I am going to use the S/R Torquer Heads from World products or Dart Iron Eagle Heads with a 72cc chamber & flat top pistons. This will give me a compression ratio low enough to use 87 octane gas.... Plus I can use the stock intake manifold... difference in cost:
    Vortec Heads: $ 520.00
    Manifold $ 325.00
    EGR stuff $ 50.00

    S/R Torquer Heads or Dart Iron Eagle $ 710.00 complete....

    I have not decided which cam to use yet, but it will be a hydraulic roller cam for bottom end. I don't really care what HP I end up with, I am looking for somewhere around 400 lb/ft of torque to come on as close to idle as possible.

    I am also balancing the engine, not because I have to, just old habits & I am convinced that they do run better balanced...

    I will still use the TBI, but I am going to flow match the injectors & install a spacer.. I may have to have the prom redone, but it will be real close...

    This should produce around 300+ HP & 410 lb/ft Torque
    All for under $2500 including the machine shop work...

    Hope this helps... :grin:

    Supergas
     
  9. Thunder

    Thunder 3/4 ton status

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    I would go with World SR Torquer centerbolt heds over Vortecs

    They are a direct bolt on and dont require a special 350.00 manifold and a bunch of EGR plumbing.

    You can do a head swap yourself its not that hard
    BUT now the can of worms is open.
    There is no sense putting on better heads unless you put in a better cam. The stock cam will never be able to match the flow better heads are capable of. So you are wasting money on the heads unless you change the cam. both Comp cams and Crane make good cams for TBI that will work with the computer.
    Same goes for the Throttle body. You should upgrade it also for more flow. Should at least do:
    Injector spacer
    Adjustable fuel pressure regulator.
    get rid on the stock TB to air cleaner spacer and replace it with a velocity stack CFM sells them under the name Powercharger
    CFM-Tech also sell anything else you need to improve tour TB. You should go to their site, as 87BrnRsd said in his post. And read every thing they have on TBI so you know what you are getting yourself into.
    Also More TBI info here. turbocity.com
    They also sell everything you need

    An Edelbrock or Holley TBI intake manifold would also help. Your stock Intake doesn't flow very well. But it can be inproved a little with some port matching and smoothing out the casting.

    Do you have headers and good exhaust? That is a must have if you want to make power also.

    With a adjustable FP regulator you may still be able to use the stock chip depending on the cam. But a custom chip for the computer would top things off nicely.

    The point I am also trying to make is making power on TBI is not as simple as putting on better heads. You have to take the time to make the whole package work together to get the results you want. Otherwise you are just spending a lot of money to get small gains in performance. But if done right 280 HP is a very atainnable goal.

    What performance mods do you have on your K5 now?
     

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