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  • Pros- Cons of a Chevy Vortec V6 conversion

    I have an 85 CJ7 with a 151CI in it now. Am looking at swapping out the motor and trans.

    Trans would be a Muncie SM420 from Novak connecting to my dana 300.

    Any comments on this setup or Novak?

    Also I am looking at a used Chevy Vortec V6 around 1995 - 2000. Have read a few posts in other places that swapping in a injected motor will be a real paid due to all the sensors that need to be installed.

    Any thoughts on this?

    I like the idea of fuel injected but could go with a carb or maybe a TBI if that was a better option.



  • #2
    The 4.3L will be a huge improvement over the 4 banger. But I say if you are going to put all the money into that stuff, go with a SBC 350. SM420 are a super beefy tranny. I would not put a carb on it, stick with the Fuel Injection.


    • #3
      Concur with keeping the fuel injection. And for some reason I like the idea of a 4.3 too. It seems like the right amount of engine for a CJ. If you want a mud racer go with SBC, though. For a daily driver I think the 4.3 would be a dandy. And the shorter engine lets you crowd the engine forward a bit more, allowing a longer rear driveshaft.

      Novak makes it sound like everything is just a drop-in affair. You will need to do some fabrication. It's not hard, they just understate the work required. Seems to me someone at Novak should write a pamphlet on how to nest a Chevy conversion into a CJ. In hindsight I think I'd rather build up a 258 than swap in a SBC, but starting from a 4 cyl the swap makes more sense.


      • #4
        I am about half way through my swap. I am installing a 4.3L TBI in front of my T5. I chose the TBI motor for three reasons:

        1. I had one.

        2. I am very familiar with how to service and upgrade the TBI motors.

        3. It is physically the same size as the port injection motor, so why not save a little $$ the first time around.

        I must say that the fuel injection wiring is NOT the hardest part of the swap. In fact, I'd say the hardest part so far has been sourcing the hodge podge of parts that I needed to make things fit, with the exhaust routing coming in a close second. I have parts from no less than 5 different vehicles ranging from a 1980 El Camino to an 89 Trans Am.

        I probably made it more difficult on myself by choosing not to buy any pre-made conversion components. I even designed and built the bolt in conversion motor mounts. I also kept the transmission in the stock location, which is about 1 inch too far back to be ideal, but I may be able to slide things forward later.

        You can find a few details here:


        • #5
          I too am in the process of a total rebuild which includes a 4.3 and 700R-4. I chose the 4.3 for several reasons;
          1. Reliable design, sharing components with the 350
          2. I could use the 700 tranny with a low 1st gear and have .70 overdrive. Couldn't do that in a CJ-5 without the shorter block.
          3. Fuel Injection
          4. Fuel mileage
          5. Good power. I should end up with about 240 HP and good torque #'s too.

          I fabbed lots of parts myself, but now there's more availability. See my Avitar