6.2 to 350 swap

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Earldub21, Jun 7, 2018.

  1. Earldub21

    Earldub21 Registered Member Premium Member

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    Has anyone on here performed a 6.2L diesel to a 350 engine swap on a K5 Blazer? Trying to figure out potential problems I may encounter. Thanks for the help.
     
    Last edited: Jun 7, 2018
  2. K5wrench

    K5wrench 1/2 ton status

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    Gogogirl has done it.
    I think she's got a build thread.
    I really like my 6.2 and it is in fine shape with only 99,000 miles.
    But if it totally grenaded tomorrow, i think i'd go 350 as well.

    I know the torque converter and trans governor weights have been discussed as needing to be changed.. possibly.
    But also heard at least one guy say it was fine with a low end rv cam.

    Motor mounts are the same.
    Oil filters are the same.
    Need to clean out the fuel tank and lines.
    I've heard there may be an issue with the radiator outlet size and hoses.
     
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  3. GoGoGirl

    GoGoGirl 1/2 ton status Premium Member

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    Previous owner did mine, M1009 converted to 12VDC and carbed 350. Gearing is stock.

    If it was my choice, I'd have gone with an LS1 instead and a higher gear ratio. Then again there's a certain elegance to the simplicity of my old-school SBC. It just can really suck when starting and warming up in cold weather.
     
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  4. K5wrench

    K5wrench 1/2 ton status

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    I don't know if mileage is a consideration.
    My 84 with a 350 cu in, 33's and 3.73's and a 700r4 got 13mpg.
    My 76 with a 400 cu in, 31's and 3.08's and turbo 350 gets 9 mpg.
    Both with Quadrajet carbs and rv cam shafts.

    The m1009 and 6.2 with 33's and 3.73's turbo 400 gets 18mpg.
     
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  5. Earldub21

    Earldub21 Registered Member Premium Member

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    I forgot to mention that the 6.2 is apart and neglected. I've had a 383 in my garage , asking me to put it in something
     
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  6. K5wrench

    K5wrench 1/2 ton status

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    I sometimes look at my 76 with it's 400 small block and think about that.. 383 that is.
    It would be so easy to eviserate that old rusty crate and build a 383 for my baby, the m1009.
    But i can't murder that old beast.
    It's greasy, rusty, and just waiting to crack the frame a third time.
    But it can pass anything on the road except a gas station.
    Those secondaries pop open and that 400 opens up with God knows how much torque..
    Everything my 6.2 isn't.
    The stately, loud, slowly smoking burble.
    The complete lack of acceleration on even the slightest incline.
    No.
    The 400 small block is a brutal gas pig that accelerates up the 10% grade at 70 mph at 1/2 throttle, the only limiting factor to it's performance being whether there will be enough gas left in the tank for the return journey.
    It is terrifying and beautiful and probably responsible for lives of many mice that foolishly chose to build their nest in it's air cleaner housing.
    Bones stripped clean by the hellish suction of the gaping maw of death.

    Then i think.. nah.
     
    Last edited: Jun 7, 2018
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  7. obijuank5

    obijuank5 1/2 ton status Premium Member GMOTM Winner

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    6.2l throttle cable is way too long. You'll need a different radiator or something because the lower coolant hose is 1.75 at the radiator and gas motors are 1.5. Had alot of trouble lately with hoses and found that out . That radiator needs the corresponding brackets and shroud.
     
  8. diesel4me

    diesel4me 1 ton status Premium Member

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    I've used muffler adapters to splice two different sized radiator hoses together more than once..:D..

    I think the torque converter from a diesel is better with the low stall speed,provided the gas engine your installing doesn't have a lumpy cam that kills the low end torque..
    GM actually put the 6 bolt diesel stall speed converter in many gas powered trucks back in the day--my brother bought a TH400 from a Chevy Van that was used as a handicapped bus that had a 292 straight six with the 6 bolt converter factory..seen a few in crew cabs with 454's ,P-30 step vans,and motor homes too..

    The govener can be tweaked to upshift later pretty easily if the shift points are too soon for your liking..

    I'm tempted to put a gas V8 in place of my 6.2 if and when it ever dies,provided the rest of the truck is worth the effort still..the biggest hassle I see,is the hydroboost brakes,I'm not sure if the diesel's P/S pump will fit and work with the brackets that came factory on a non hydroboost gas V8 or not,and if not,finding the right brackets will prove difficult..or expensive at least..
     
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  9. Earldub21

    Earldub21 Registered Member Premium Member

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    Milage isn't really a concern. 3.08s? yuck! If I have those I may upgrade to a 3.73 for highway and gives me more power to play in the mud with, should I choose to.
     
  10. campfire

    campfire Adventure is out there! Premium Member

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    Hahaha. :haha:
     
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  11. campfire

    campfire Adventure is out there! Premium Member

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    I haven't personally done this, but a bunch of guys have added hydroboost to gasoline rigs using the diesel pump and stock bracketry.
     
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  12. GoGoGirl

    GoGoGirl 1/2 ton status Premium Member

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    x2, previous owner did that to mine, I have Hydroboost with a swapped 350, was a 6.2 diesel when stock.
     
  13. K5wrench

    K5wrench 1/2 ton status

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    Yeah, the military ordered m1009 Blazers with 10 bolt axles, 3.08's and a gov loc rear carrier.
    Thus the reason I swapped between my 86 m1009 and 76 K5.
    3.73 is much better all around with the 6.2 and 33 inch tires.
    Getting rid of that gov bomb carrier was a bonus.
    Who's bright idea was it to allow a 100 rpm difference in wheel spin before locking the axles?!
    Icky.
    Much prefer the open carrier and a lunchbox locker to the gov bomb.
     
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