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  1. #1

    Default 94 gmc engine replacement

    I'm looking to relace my 5.7 with something smog legal and built for towing.
    GMPP has a direct replacement but it is for 96-99. Any suggestions would
    be appreciated.

  2. #2
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    murdog94's Avatar
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    Default

    That is a Vortec motor, your 1994 is a TBI... Best bet is to refresh your motor and put in a mild towing cam some headers, cold air intake, mabey a little bore and stroke etc...... and then everything will still smog great... There are 50 state legal headers available for your truck.. Also for towing depending on what you are hauling it would be a good idea to go to a mild shift kit Jimmie might have some input on the tranny side.. Also stepping up the differential gears to 3.73 or even 4.10 (if this is a dedicated towing rig) will make your truck tow like nobodys business...
    Mike

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  3. #3
    Master Mechanic Silverado Junkie's Avatar
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    Default

    Quote Originally Posted by murdog94 View Post
    That is a Vortec motor, your 1994 is a TBI... Best bet is to refresh your motor and put in a mild towing cam some headers, cold air intake, mabey a little bore and stroke etc...... and then everything will still smog great... There are 50 state legal headers available for your truck.. Also for towing depending on what you are hauling it would be a good idea to go to a mild shift kit Jimmie might have some input on the tranny side.. Also stepping up the differential gears to 3.73 or even 4.10 (if this is a dedicated towing rig) will make your truck tow like nobodys business...
    X2, I think after you rebuild your motor you'll have one awesome running truck.
    1995 Silverado,Z71, 3-inch lift,2-inch leveling kit, SkyJacker Suspension, short ram-air intake, throttle body spacer, MSD ignition coil, straight pipes

  4. #4
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    Default

    You could get a different intake manifold to use your TBI setup with the vortec heads on that crate engine.. They're not cheap though at around $400.

  5. #5

    Default

    You all have me doing a bunch of research now. I have found that I can get a 50 states intake and cam from edelbrock. I've been looking at stroker kits and have found that there are a lot of options. Do I want to go all the way to a 383? Is their a bolt on kit that doesn't have clearance issues? Or do you all have suggestions on what combinations you would consider? Thanks for the help.

  6. #6
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    Id go all the way to a 383 with a good flowing intake, and came.. Make sure you keep EFI though that will net you the best effiency... Also the 383 stroker kits are fairly common and therfore usually cheaper.. And a good set of headers... And as i said tranny upgrades are almost required.. And gears.. That is what i would do in stages obviously since all of these take time and money... But for an ultimate tow rig that is about the best you can do and keep it a small block with out forced induction...

  7. #7

    Default

    So i've narrowed it down for economical purposes. There is the gm 12568758 and the 1252070, which seem to be factory replacements for my application. One is for the 8 Is there any reason other than legal purposes that either of these engines wont work and be smog legal. And which one would be better for pulling.

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