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GM Goodwrench 350

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by santana, Sep 2, 2003.

  1. santana

    santana 1/2 ton status

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    I'm picking up one of these babies this weekend and I was told they only put out about 190 HP and was wondering what I can add to pick up a couple of extra ponies, I've got a Performer intake wich I will probably also get a 600 cfm performer carb to go with it. Besides that and adding a set of heders what else can I add? Opinions.? /forums/images/graemlins/ears.gif

    Am I right to go with this stuff?
     
  2. Hossbaby50

    Hossbaby50 3/4 ton status

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    Don't mess with the internals of the motor or you will void the warranty. As far as performance things for that motor:

    Headers
    Performer intake
    Qjet carb (800 CFM) vs. the 600 you are looking at
    MSD ignition box, wires, coil (yes they do work)
    good flowing 3" or dual 2.25-2.5" exhaust
    performance mufflers & cats
    advance the timing as far as possible without pings
    K&N filter
    synthetic oil

    If you don't care about the warranty (which you should) then:
    roller rockers
    new cam
    vavle job
    deck the heads
     
  3. 88Silverado

    88Silverado 1/2 ton status

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    Dude...Read this first then have at it /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif
    GMGoodwrench Buildup
     
  4. santana

    santana 1/2 ton status

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    I think I'm gonna start with the intake and carb. I'm hoping the serpentine set up on my donor truck works and will be using that too, oh and the headers also just enough to get it going. Then I'll continue with a dual exaust and work from there.. $$$$$$ is a major issue.. /forums/images/graemlins/grin.gif

    Thanks for the advice on the internals/warranty, I really dont want to mess with that. /forums/images/graemlins/thumb.gif

    Do you think a Qjet is better than a Parformer for this application cause I believe my stock is a Qjet dont know what CFM tho'
     
  5. Hossbaby50

    Hossbaby50 3/4 ton status

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    Qjets are better offroad carbs then Performers and they also flow better. The qjet is also pretty good on gas because of the small primaries.
     
  6. santana

    santana 1/2 ton status

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    Thanks, I'm gonaa try my stock carb and see. Hopefully I can get started on this by this weekend.
     
  7. Shaggy

    Shaggy 3/4 ton status

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    <font color="green"> Scoggins-Dickey tested one of them with headers and a 4 barrel and got 265hp out of it, IIRC. I have the motor and put a comp cams Extreme (256 or 258 I think) K-kit in it before I even put it in the truck. Even if something happens to the motor, odds are they'll never be able to tell that the cam is different. With 38s and 4.10s my truck would get up and move pretty good with it, and I could light the tires up in 1st if I wanted to. That was with a stick, so no brakes were used to get the tires going. Time will tell what happens when it's pushing the 42s with 5.13s. If I could find a copy of Desktop Dyno I would know better what kind of power it has, but I'm guesstimating it's around 300hp. I also have headers and run an Edelbrock carb, which has been worked over and runs great at angles, BTW... /forums/images/graemlins/thumb.gif</font>
     
  8. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    I had a 454 Goodwrench motor in my old 75.

    Definitely go with the q-jet over the AFB (square bore) design. The AFBs suck bad off road. Even with an "off-road" kit. Without the kit, just hitting a speed bump would make my 75 with a 454 stumble. Edel tech told me not to bother with the kit when I told him what I was doing, it's mostly to control slosh (like the speed bump). Anyway, best carb I have ever run bar none is the Edel Q-jet. If you can aford it, that's the way I would go.

    Edel dual plane performer intake is a good investment. I have run them on several engines, no complaints.

    IMO, don't go too far on the exhaust unless you really want high rpm (past 4.5-5k). Big will hurt the bottom a little but helps the top allot. I specifically run a single 2.5" on my truggy because I don't care about anything past 4k...

    A good set of Thorley tri-y headers would be on mine if I really wanted to spend some money on making power.

    Beyond that (and to really wake that up) a cam upgrade will be good, but make sure it matches the rest. I ran a matched Edel performer RV setup in the 454 and it was really sweet. I also successfully mix-n-matched on several including a 455 in a 66 GTO (semi) sleeper that worked well, but you gotta do your homework... The key is to have everything matched up...

    Further than that, your past the point of diminishing returns. Gets expensive for small gains, and they usually come with compromises…

    This is just my view, others may well disagree…
     
  9. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I'll run your combo in DD 2000 if you PM me with specifics.
     
  10. Shaggy

    Shaggy 3/4 ton status

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    <font color="green"> Tell me what you need to know and I'll shoot it all over. /forums/images/graemlins/thumb.gif </font>
     
  11. santana

    santana 1/2 ton status

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    Well I gotta do this within the next week or two, I really need it running and would like to do whatever is goin on before I put it in.

    All your opinions count, Thanks /forums/images/graemlins/thumb.gif
     
  12. Blue85

    Blue85 Troll Premium Member

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    The stock 350 was around 190hp. The Goodwrench is generally advertised as 240-250. I have one with no modifications and I am about 100hp over stock. That is just headers, duals, curve kit and electric fans. Of course the stock engine was a full smog 305 /forums/images/graemlins/rolleyes.gif
     

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