Holley TBI vs. Turbocity 454 TBI, 350HO Upgrade

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Hoover87, May 4, 2002.

  1. Hoover87

    Hoover87 Registered Member

    Nov 7, 2001
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    Hello all. I have searched the archives and have found a number of posts regarding TBI's, but I'm still having a difficult time making a choice. Here's what I'm doing:

    In an '87 p-up I'm replacing a tired 305 TBI engine with a brand new GM 350 HO crate engine. The engine is ordered and on its way. I also ordered the Vortec to TBI manifold to go with it. A new chip is planned too, probably Fastchip. The only thing left to do is decide what to feed it with. I'm overseas so going to a junk yard is not an option, I have to buy new.

    I am looking at two options, the Holley 670 cfm TBI or a 454 TBI from Turbocity. How do these compare? I've read mixed reviews about the Holley...Fastchip also said that it doesn't keep its adjustment and they don't recommend it. In fact Fastchip went as far as saying that they can't build a chip for me if I use the Holley. They did however recommend Turbocity.

    I talked to Turbocity and they recommend their 454 TBI. I'll agree with that, except the price is the killer....over $500. I don't mind paying, just as long as there is a good reason.

    What's your input, thoughts, comments?

    One additional, I also plan to bore out the intake to match the 2" bore of the throttle body. Has anyone here done this? Should I expect problems?

    Thanks for any input.

  2. Nrose07

    Nrose07 1/2 ton status

    Mar 29, 2000
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    Salem ,Or
    I would recomend turbocity, but I can't! Didn't have the $500 to buy it so I got the Holley, won't recomend that either. You get what you pay for! And yes you can bore the throttle bores out to 2.050" Go alittle larger because the TBI's are larger than 2.00" You won't have any problems, I didn't.
  3. Thunder

    Thunder 3/4 ton status

    Jul 20, 2000
    Likes Received:
    Northeast Nevada
    If you are using the 454 TB on a 350 you have to bore out the intake manifold.
    Beings you said you were overseas, I recomend Turbocity. I have used many of their products and am satisfied with their parts and the performance gains i have got with them. Their tech people have been pretty helpful but they can be kind of vauge in their answers sometimes. probabally because they are in Calif and have all those smog laws.
    Turbocitys TBs and Fi kits are all GM componets. So your computer and stock wireing harness will interface with them no problem. You can get parts for them anyplace that sells GM parts. The Holley may be harder if not impossible to get parts for overseas.
    The only thing you will need is a Idle Air controll adapter for the 454 TBI. TC sells them also.
    Turbo city can also burn you a chip that willl go with their TB and your engine.
    I have also dealt with fastchip.com I have a stage one chip in my K5 they also know what they are doing. It works very well.
    If you dont want to spend 500 for a 454 TB and get your manifold bored. Turbocity also has a high flow TB for $230. I think if flows around 600 CFM .That and a set of flowmatched injectors and adjustable fuel pressure regulator would also run pretty good on that 350.

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