Need Engine Advice

Discussion in '1973-1987' started by GMC Guy, Mar 19, 2009.

  1. GMC Guy

    GMC Guy Member

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    Livermore, CA
    i have a farely new 350 crate engine. it's runs very strong, but i'd like to add some power to it. I'd like to try to get around 350 hp. i'm not sure exactly how much horse power it's putting out now, i'd imagine around 250? anyway, i'm already looking at an edelbrock carb & intake, and hedman headers (kinda on a budget :( ). just looking for any advice from you guys out there. maybe someone knows what works well, or what combos make good power.

    thanks.

    oh and it has to be smog legal... :mad:
     
  2. texascowboy

    texascowboy Member

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    Texas
    okay to start out, what year model is the truck?
    anyway it sounds like you already are going in the right direction,
    the items you have should increase your power as far as how much I'm not real sure. I have an 83 and I added a carb,intake and even headers and it gave me a boost of power and to keep it legal I put the stock breather back on it and ran some dummy hoses and mine passed but, it also depends on where you take it. hope this helps good luck!
     
  3. GMC Guy

    GMC Guy Member

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    it's a 79 GMC 1/2 ton.
    and thanks for the help :)
     
  4. texascowboy

    texascowboy Member

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    no problem.....:)
    its a 79 and you have too have it "smog legal"?? man that is weird.
    anyway, the set up that you are looking at should do the trick, if you stay with the 305 but, I would diffently do something to reinforce for the weight.
    good luck...:D
     
  5. GMC Guy

    GMC Guy Member

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    well in my liberal state of california, we feel it's necessary for all vehicles built after 1975 to require smog.... :rolleyes: trust me, it sucks

    but actually it has a 350, not a 305...big difference there :p
     
  6. Jeffrey

    Jeffrey Member

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    Increasing horse power?

    If you dont wish to bore the engine or change the stroke for cubic inches,which increase horsepower, the only other ways to increase horse power is Carb, headers and possibly distributor recurve, but the golden rule is "No replacement for displacement" and cam change? something like boring it .030 over and changing cam can still be ok on emission test. Can increase exhaust valves to 1.600 from the stock 1.500 and machine shop can increase exhaust port size with 60 degree cutter. I used to run a NAPA machine shop . if i remember .030 over adds 6 or 7 cubic inches, not sure on horsepower
     
  7. Jeffrey

    Jeffrey Member

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    horsepower increase

    chevy small blocks were always hurting in exhaust flow, not intake flow. Alot of people aways ask me to make heads 2.02 size from 1.940 But truth is 1.940 intakes are fine, exhaust is needing opended up, so I would port and polish exhaust ports way out. got to be carefull can go to far..
     
  8. drabo

    drabo Member

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    I don't know what type of block you have but this package will give you what you want and on a tight budget.

    http://www.sdparts.com/catalog/Engi...Heads/SDPCVortecCylinderHeadsandHeadKits.aspx

    1. Cam swap around 1500rpm range. If your block is set-up for a roller cam that is the way to go. If it is the is two raised threaded holes in the lifter valley and you have a 1 piece rear main seal.

    2. Vortec heads. They put out good power out of the box. The main problem with them is they can't handle a radical cam. That shouldn't be a problem if your only going for 350hp.

    3. Intake needs to match the cam so Performer 1500 RPM or the 1500 air gap.

    4. Roller rockers. also change the ratio. This will open the valves a little more allowing them to breath a little better.

    5. Edlebrock 750cfm carb it's easy and simple to use. You need to feed the beast. Holley's are also great and if your are good with carbs the adjustments and tweaks are endless.

    6. Spark, you got to set the beast off. A good HEI distributor or just a good distributor period. I use a Mallory Unilite. Has no points and no adjustments except timing. But it is sensitive to voltage surges so run a filter.
     

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