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LS1 in a K5

Discussion in 'The Garage' started by PsychoticDeadGuy, Aug 28, 2005.

  1. PsychoticDeadGuy

    PsychoticDeadGuy 1/2 ton status

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    I just talked to my neighbors dad, he works for GM. He said he could get me a LS1 block and heads for nothing but i need to know if it will bolt in and if everything will bolt up the same. i will put a new 700r4 behind it and will rebuild my np208. but does anyone know if the mounts are in the same place and if the block is the same length?
     
  2. 1979jimmy350

    1979jimmy350 1/2 ton status

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    you will need a adapter for the engine mounts. The engine mount hole on the block are in a different spot. The tranny will bolt up but you will want to run a 4L60-E so you do not run in to computer problems
     
  3. sled_dog

    sled_dog 1 ton status

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    Bunch of differences. It can easily be done, but the motor is taller, (most of it being below the motor mounts I believe) so you need to modify the crossmember. Peterson's swapped a 6.0L into a K5, which is the same dimensions. Also you will need a 4l60E(newer 700R4 basically), the bolt pattern of a Gen III motor is different by I believe 1 bolt hole. Mounts are different but I know someone sells mounts so you can bolt them in place of a Gen I motor. I really want to put a Gen III in a K5 or a newer IFS truck.
     
  4. sled_dog

    sled_dog 1 ton status

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    Shouldn't be any issue with computer really, as long as the chip is programmed for a manual and not an Auto.

    One thing, this is going to be very expensive. Rotating assembly and block are easy parts. Now you need ALL the little bolts and things, intake, computer, wiring harness, injectors, coils(EXPENSIVE), plugs, wires, oil pump, blah blah blah blah. Can't say I would consider passing up a free LS1 but it will be a real big project.
     
  5. PsychoticDeadGuy

    PsychoticDeadGuy 1/2 ton status

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    ya, big project all right...but now that i think about it i will probably get a mid to late 90s 350 out of a denali that runs. i can get machine work done for free on it and my dad can get me parts for next to nothing compared to what most of you guys have to pay. he owns an auto parts chain. so, a newer 350, not an ls1 with a cam and intake that i will get bored .30 over...will this work if i can get my TBI unit and intake to fit it? i dont have the money to get TPI and still want to be able to climb a hill so a carb is out...will this work then?
     
  6. sled_dog

    sled_dog 1 ton status

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    latest you can use is a 1995 350 and its pretty much if not exactly the same as a 1987 350. 96 was Vortec and the intake patterns are different. Though I think GM makes a TBI intake for the Vortec pattern heads.
     
  7. PsychoticDeadGuy

    PsychoticDeadGuy 1/2 ton status

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    ok, so it must be a late 90s engine because he said it was a vortec engine. so, where could i find a TBI intake for a vortec engine? i really want to do this swap so i will have alot more power without spending too much money...thanks for the help
     
  8. sled_dog

    sled_dog 1 ton status

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    A LOT might be an overstatement. Vortecs have about 50 more HP but also the better fuel injection system and computer controls. So I'd bet on like 30 hp between the heads and roller cam. Worthwhile swap I'd say though. Cam probably wouldn't be worth it. Cam would have to be mild to work with TBI, and roller cams are expensive just to get a mild one($275 is about the cheapest and thats a Factory GM LT4).
     
  9. PsychoticDeadGuy

    PsychoticDeadGuy 1/2 ton status

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    ok, so not a ton more HP but my current engine is running on its last little ponies...so it will be alot for my truck.so do you know where i could find a TBI intake for the vortec engine?
     
  10. sled_dog

    sled_dog 1 ton status

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  11. PsychoticDeadGuy

    PsychoticDeadGuy 1/2 ton status

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    alright, thanks alot. i will look up the edelbrock stuff and see what that would cost me.
     

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