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diesel swap?

Discussion in '1982-Present GM Diesel' started by im_2gr82h8, Apr 4, 2001.

  1. im_2gr82h8

    im_2gr82h8 Registered Member

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    I have a '80 GMC Jimmy that i love to death. I have swapped the puny 350 for a olds 455 that was bored 30 over to 462 added a rv cam and some other nice extras. But now i have run into a problem, I am a student in college and working almost full time and i can no longer afford to fead my baby.

    I get somewhere between 0 and 4 mpg depending on my mood. I was thinking that swaping my BB :( for a diesel would get me back into the mileage that i need to keep it.

    Heres the deal i have no idea what this would take, some people have told me that i would need to install different fuel systems and brakes etc. but no one has given me a strait answer. Has anyone else done this? Or would it be a better idea to buy another k5 that is already a diesle and then swap all my mods (1 ton axels, lift,etc.) to the diesel k5?
    thanks for the help
     
  2. HarryH3

    HarryH3 1 ton status Author

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    Let's put it this way, the money to do the swap would buy several years of gas for your current setup. [​IMG] Unless you can find someone that's giving away a good, running diesel. [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
    It's a great day to be alive...
     
  3. OFFRDK5

    OFFRDK5 1/2 ton status Premium Member

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    Forget about doing the swap. Buy a Diesel if you want one.


    SK-15
    J**P...it's whats for dinner!
    <A target="_blank" HREF=http://SK-15.coloradok5.com>http://SK-15.coloradok5.com</A>
    Roads? Where we're going, we don't need any roads!
     
  4. NewK5Guy

    NewK5Guy 1/2 ton status

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    It's not impossible, but there are lots of things you'd have to do. Yes, the fuel system would probably have to be replaced. You could flush it, but there's too much risk of some gas contaminants sneaking in. Brakes could stay, but you wouldn't have any power booster. You could concieveably swap in the hydro boost system(the diesel should already have the hydro boost ps pump) as the power booster adapter is only some 3" or so long and sits in the place of the vacuum booster.
    Yea, it'd take some time. Try to find a late 80's 6.5 turbo diesel Jimmy cheap and just swap your goodies over. You'd probably be better off.
     
  5. DieselDan

    DieselDan 1/2 ton status

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    Sorry, 6.5 didn't hit the market 'til '93, turbo 6.5's '95 I THINK! But the eighties were strickly 6.2, I KNOW!
     
  6. AgDieseler

    AgDieseler Certified Scrap Producer Premium Member GMOTM Winner

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    In 1989, Gale Banks engineering was contracted to make a turbo system for the 6.2L, and was a dealer installed option until 1992. When the 6.5L was released in 1993, it was turbo-ed. From then on, we in the GM light trucks have only had the option of the the 6.5TD. Vehicles like the hummer got the NA version. That's the gospel according to GM.

    But to actually respond to the original question, it's very expensinve to do a gas to diesel swap, and unless you're commited to keeping this vehicle for a very long time, it's not worth the money. The only exception would be to find a complete running diesel truck, and swap in the entire engine and accessories along with the correct torque converter. Theoretically, it then boils down to paying for little more than elbow grease, and fluids.

    I'm a student at Texas A&M, so I feel your pain of being chronically poor.

    David Oliver
    '85 'burban - 6.2L J NA
    5.5"lift, 35"BFGs
    *B&B 6.2L TD and beefed T-700 coming soon*<P ID="edit"><FONT SIZE=-1>Edited by AgDieseler on 04/04/01 08:57 PM (server time).</FONT></P>
     
  7. im_2gr82h8

    im_2gr82h8 Registered Member

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    Thaks for the help. From what I've read here and what people have told me, I think I'm just gonna keep my eyes open for a cheep diesel and move all my mods to the new truck.
     
  8. pcorssmit

    pcorssmit 1/2 ton status

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    Not sure what you're running for tires, gears, etc, but chances are that going from a built 455 to a 6.2, you're going to be pretty dissapointed.

    Seems you ought to be able to get more than 4 mpg out of your truck. Have you tried tweaking the carb, ignition, etc? Maybe backing out of the throttle a tad? Even at 1/2 throttle you'll still have more power than a 6.2 NA.

    Let's say you can get your 455 up to 7.5 mpg. Let's also say you'd get 15 mpg w/a 6.2, and that you can get the whole conversion done for $2000, plus your labor. If gas = diesel = $1.50/gal., it would take 10,000 of driving (very slow, mind you) w/the 6.2 just to break even.

    Have you thought about buying a cheap commuter car? Saves lots of wear and tear on mud tires, as well as gas. Plus you never have to worrry about getting the K5 put back together in time for work.

    Pete

    '83 K5, 350 TBI (ex 6.2), 700R4, NP208, Dana 60/14 bolt, 4.56s, Detroits, 3" lift, 15-39.5x15 TSLs
    '97 Dodge 2500 4x4 CC LB Sport, Cummins 5 spd
     
  9. im_2gr82h8

    im_2gr82h8 Registered Member

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    I am running a 6" lift, 4.10 gears and a built up 350 trannie. No overdrive :( Oh yeah, the rubber is 35x14.5x16.5 SSR's. I hate the 16.5" rims, but I needed them to clear my rear drums. I have a rear 14 FF, and a dana 60 up front.
     
  10. pcorssmit

    pcorssmit 1/2 ton status

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    The Swampers are part of your milage problem. They have a ton of rolling resistance compared to regular A/Ts or M/Ts.

    With 36's and 4.10s, I don't think you'd see a justifiable mpg increas by going to an OD tranny.

    15's clear 14 FF drums no problem, even with 4-1/8" backspacing. Front 60's will take a lot of grinding, but its not impossible, mine works just fine. However this won't improve milage.

    Pete

    '83 K5, 350 TBI (ex 6.2), 700R4, NP208, Dana 60/14 bolt, 4.56s, Detroits, 3" lift, 15-39.5x15 TSLs
    '97 Dodge 2500 4x4 CC LB Sport, Cummins 5 spd
     

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