LS V8 Swap! 1970 Chevrolet Monte Carlo

The 1970 Monte Carlo was Chevy’s first foray into the personal luxury car segment of the market. It shared its roots with the Chevelle Malibu as well as the Pontiac Grand Prix. At the time of its introduction, it had the longest hood of any car built ever by Chevrolet (a full six feet). This beautiful first-year edition looks like a survivor until you pop the hood and find that a more modern 6.0-liter LS motor has been dropped in. This sweet Chevy is in Pompano Beach, Florida, and is available here on eBay through a dealer with the current bid is $15,900 (no reserve).

First-generation Monte Carlo’s were built from 1970 through 1972 and produced sales of 146,000, 128,600, and 180,800 units in each of those respective years. There was a slight dip in ’71 due to a labor strike against GM in late 1970. The new marque was quite popular, but things really took off when the Colonnade-styled intermediates came out in 1973, and Monte Carlo sales jumped to 250,000 and more. A commonly used engine in the Monte Carlo was the small-block 350 V8, but you could even get an SS 454 in 1970 and 1971.

We don’t know the history of this Chevy as it’s being offered by a dealer. Whatever motor was under that expansive hood has been replaced by one from the GM LS family of engines, in this case, a 6.0-liter  or about 364 cubic inches). Over 20 years, an LS could be found in anything from a police car to a Silverado pickup. There is no mention as to how this engine was built, so we don’t know how much horsepower the car picked up from the conversion.

A TH-350 automatic transmission is part of the hardware (could be original) along with a 12-bolt rear end, and a Flowmaster dual exhaust system has been added. The body looks nice and straight and perhaps the shiny black paint is original, though one of the hood hinges doesn’t seem to close 100%. The interior comes across as standard Monte Carlo fare (except for the steering wheel), including crank windows as opposed to power-assisted. The seller has provided a couple of videos to demonstrate this sweet Chevrolet. Question: would the buyer of this auto have been better served with a period-correct 350 rather than the LS swap?


  1. KC John Member

    I love the change to a ls. Wish they’d done the transmission upgrade to complete the happiness. If you want trouble free power the LS seems to be the answer. I’d feel differently if this was an original big block. Don’t hate me original only folks.

    Like 17
  2. Moparman Member

    I see A/C vents, but no components under the hood. A black on black beauty like this in Florida has got to be a hot ride! GLWTA!! :-)

    Like 7
    • 19sixty5 Member

      The vents are just that, vents. They simply admit outside air into the car. They are controlled by the pull knobs on the kick panels. That mile long fuel line and the cheap filter are a fire waiting to happen. Add AC, correct the fuel line issue and ditch the steering wheel and half moon headlight covers you have a decent cruiser.

      Like 2
      • Glen

        Yep… good ol’ Astro Ventilation and a rubber fuel supply line hovering millimeters over the headers. Looks like high school.

  3. Ike Onick

    The LS Gods have smiled upon the LS-ites!!!

    Like 2
  4. Tony Primo

    The swap looks okay, but really needs a/c, 4 speed automatic and factory fuel injection put back on to be anything special.

    Like 5
  5. joenywf64

    If that’s a carburetor on there, is there a way to machine this motor to accept an HEI disributor(w/single integrated coil) & eliminate the computer, electronic boxes, & sensors?
    This setup seems a step backwards, since HEI eliminated the coil wire back in ’74.

    Like 1
    • Tony Primo

      That is a carburetor on there Joe. You can’t run an HEI distributor on the LS engine as the camshaft doesn’t have a gear on it to drive the distributor.

      Like 2
  6. Pnuts

    All the trouble to LS swap an engine and put a carburetor on it. That explains the A/C delete. Why not leave the small block?

    Like 1
    • 19sixty5 Member

      The LS swap into a 70-72 Monte Carlo is actually quite simple. The oil pan, headers and engine mounts are the same for all the 68-72 GM Chevelle and other A body cars. Converting it to a carb makes the swap even more simple as there are less sensors and wiring to deal with. Personally I would have gone with the factory EFI system, and a newer OD trans, they are pretty much bullet-proof. This is not an AC delete car, it never had it! The LS series engines are a huge improvement over the typical SBC in almost every category, although they are butt-ugly!

      • joenywf64

        What about 383 Chevy strokers that make 450HP 460+ FTLBS that i see on ebay for $5700-7000? Aren’t those a lot cheaper & less
        installation-aggravating than a crate LS?
        Or are you talking about an LS from a wreck? How much would one of those cost along with all the other things nec to make it run?
        I personally would rather have one proven HEI coil under the hood rather than 8 exposed ones on top of the hot valve covers.
        & no computer.

  7. 19sixty5 Member

    I can’t speak for the builder of this car, and no idea of why he decided to LS it. It could be he had access to an engine dirt cheap or even free. Maybe he didn’t feel the need for 450 hp engine and just wanted a reliable cruiser. I’m not critical at all of the SBC or the HEI, I’m running one in my SBC and BBC engines. Regarding heat and the coils on top of the hot valve covers, I bet there is more heat at the HEI than LS coils in the open airstream. And… if you lose the HEI coil, you don’t run at all, period. Lose a coil on an LS, you have 7 more. Old school, new school, it doesn’t matter, have fun with whatever you build. Again, no idea of why the original builder went this way, I likely would have gone back to a 350, unless…. I just happened to have something else laying around.

  8. PRA4SNW PRA4SNW Member

    SOLD for $17,999.

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