How to build cheap 400hp 350

Discussion in 'High Performance Modifications' started by Eric_04, Feb 15, 2009.

  1. Eric_04

    Eric_04 Veteran Member

    Nov 10, 2008
    Oakfield, WI
    Hey guys, I figured if anyone could help me out you guys could. So here goes.. a friend and I are planning on putting a 350 and turbo 400 in a 94 gmc jimmy. The simplest way to describe it is that it used to look like a jimmy but is now a pickup, everything behind the front seats was cut out except the floor and we enclosed the cab and put a cage in it. It basically going to be a field racer. That being said, we have a power goal of 400hp but want to do it as absolutely cheap as possible, considering what its going in. We have a complete 350 out of a truck, but I am unsure of the year, the heads, etc. It will be coming apart in the next few weeks since we just removed the drivetrain this weekend, hopefully being able to sell some or all of it from the jimmy, if anyone wants some v6 vortec stuff, or transfer case, or tranny, or front diff, etc, I have it lol. Everything is completely functional except the motor which has a knock. Basically I'm looking for the cheapest combo that we can come up with that can get us close to the 400hp mark. Thanks for the help.
  2. cmonson

    cmonson Veteran Member Gold Member

    Apr 7, 2006
    Calgary, Alberta
    for a rig like that, do NOT build for HP, build for torque.

    For a mud bogger, torque is what gets you through the mud not HP.

    If it were me, i would take that 350, make just above 9:1 compression, install a small cam, do what you can with the heads, and call it a day. I would set a goal of 350ft'lbs of tq.
  3. Eric_04

    Eric_04 Veteran Member

    Nov 10, 2008
    Oakfield, WI
    I guess I should state that it will not ever be a mud bogger, only 2wd now, and it will occasionally be driven on the road. It will be driven in the fields and what not only when they are dry or at least close to it, becuase driving it in the mud would be pointless.
  4. hhott71

    hhott71 Veteran Member Lifetime Gold Member

    Mar 30, 2001
    Joplin Mo. 64801
    A mild bracket cam
    .480" lift 230º duration
    decent heads
    From already owned Fuelie's, Vortecs or cheap (NOT CHINESE) aluminum heads Hey Trick Flows are $1000 or less a pair.
    Plus the normal bolt ons headers intake 600-700 cfm carb
  5. warped

    warped Veteran Member Lifetime Gold Member

    Check out the roundy-round guys and their claimer motors. You might want to look at Northern Auto parts or Speedway Motors for ideas. Good luck.
  6. Alex71RS

    Alex71RS Veteran Member

    Feb 13, 2000
    Apple Valley, CA 92307
    EXACTLY^^^^^^ I have a formula for a 400 horse 350 that is almost identical to that. Early 90s one-piece rear seal 350 truck shortblock, vortec heads (cut down the guides, bowl work, good springs), a Lunati Voodoo hydraulic cam (60103: 227/230 @ .050, .489/.504 lift on a 110 lobe center) Air-Gap intake and a 750 Holley. If you run the stock dished pistons, remember to mill the heads to achieve a 58cc chamber (about .040 mil-off) and use a steel shim head gasket (.015). If you decide to upgrade the pistons to flat-tops, just do the math and figure out what piston will give you a 10:1 compression ratio with the 64cc chambers. This combo will work it's best with a 10:1 compression ratio. It's probably the cheapest 400 horse motor you will ever build.
  7. Chaindrive

    Chaindrive Veteran Member

    Sep 13, 2008
    Cornpatch, USA
    Cmonson nailed it: Build for torque on a 4x4.

    The best way to do this with a 350, and still stay on a budget, is to build a 383 stroker.

    Stock 400 cranks, balancers, and flexplates are cheap and easy to find. Use your 5.7 rods and some $150 hypereutectic pistons and keep the compression below 9.5 or so. You don't need a forged crank or pistons. Use a good 'torque' cam and decent heads and go have some fun!

    You should meet, or come real close to, your 400hp goal and have more torque than a 350 for about the same money. Other than some minor block clearancing, turning a 400 crank to fit a 350 doesn't cost any more than turning a 350 crank.
  8. Led Zep

    Led Zep Veteran Member

    Mar 13, 2008
    Get a 96 -00 long block with vortec heads and roller.Will make 400 HP easily.
  9. Led Zep

    Led Zep Veteran Member

    Mar 13, 2008
    Popular Hot Rodding did a David Vizard Build,350 made 447 HP on unported vortec heads.Used a short duration cam also, 224 duration.
  10. woody80z28

    woody80z28 Veteran Member Lifetime Gold Member

    Sep 8, 2004
    walton, ny usa
    I have almost that EXACT combination. Desktop dyno tells me it makes 417hp at 6000rpm and it runs great on the street.

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