Live Auctions

LS-Swapped! 1974 Rolls Royce Silver Shadow

One of the most common things we see in a post comment section when we feature an unusual car with engine issues is the famed “LS swap it” universal solution. That’s exactly what someone has completed with this 1974 Rolls Royce Silver Shadow that is listed for sale here on eBay. Even as a British car fan, I have a tough time arguing with this swap if the original engine was damaged or missing. Other folks must agree as 31 bids have already driven the no-reserve auction to $12,600 with plenty of time remaining. The Silver Shadow is located in Colleyville, Texas.

When it was introduced in 1965 as the first unitized-body Rolls Royce, the Silver Shadow was considered the most advanced car to ever leave Crewe. Although we don’t know what happened to the original engine, it appears that the rest of the car is in very good to excellent condition (although I’m bothered by the exclusion of front seat upholstery from the photographs). The paint is new within the past year and the suspension, which is notoriously complex, has supposedly been rebuilt.

I put this table together based on internet information, so take it with a grain of salt, but it does illustrate that the LS/GM6L80E seems to bring a pretty nice performance enhancement to the Silver Shadow. I doubt that the minimal weight increase would affect the suspension greatly. The increased horsepower and doubling of gear ratios should improve the original car’s 0-60 time of 11.0 seconds.

While the walnut dash finish is cracked, that classic British luxury is still present in droves. I don’t see anything that has changed cosmetically due to the swap although I really wish I could see more of the interior.

It’s a pretty ugly engine compared to the original one, but it does make for a much cleaner engine compartment. One glaring omission to me is a lack of air conditioning – unless you are in northern Canada this is becoming more and more of a requirement. If one is going to be driving a car like this around, wouldn’t one want to be separated from the hoi polloi by the window glass? Just kidding, but I would prefer that air conditioning was either fixed or added. What do you think about this swap? Would you rather have an original or this modified Shadow? Let us know in the comments!


  1. Raymond

    At least the LS is reliable, funny how RR engines are world renowned for reliability and durability, yet every rolls I’ve ever seen is in a shop needing engine work…. something is fishy about that…yet prob very comfortable sitting on the side of the road…

    Like 13
    • Dave

      Funny, but their aircraft engines don’t seem to have that problem.

      Like 5
    • Bruce Member

      the usual reason for unreliability is they usually stay parked in their garage. You don’t see that issue as often in the uk. these cars are built to be driven not treated as a princess to come out on holidays

      Like 6
    • Gerard Frederick

      It´s called propaganda and as with practically all propaganda it´s a lie. To claim RR was reliable is like claimimg AIDS is fun.

      Like 2
      • Laurence

        Gerard: to you anything from my country is “propaganda” and no good–be it Aston Martins, Jaguars, Rolls Royces, etc. You have even made light of the bombing of Great Britain by the Nazis, saying that it was “propaganda” and only just “a nuisance”. I think the families of the many dozens of thousands who died in the bombings would disagree. I would be interested in knowing where all this is coming from. What has Britain done to you personally? Have a nice day.

        Like 18
    • Bill McCoskey Bill McCoskey Member

      Rolls-Royce cars ARE known for their reliability, as long as the maintenance is performed when required. Failure to maintain these cars results in far more expensive repairs.

      So when you see a Rolls-Royce [or Bentley] in the shop, it’s generally for maintenance, or for repairs, because it didn’t get that all-important maintenance!

      I’m familiar with both sides of the coin, as I ran a private Rolls-Royce service and restoration shop for 30+ years.

      Like 19
      • Gerard Frederick

        Thanx Bill for the enlightenment. Since you have tons of hands-on experience and state your case without any passion, I realize that I was wrong in my assesment. Cheers and Beers! GF

        Like 1
  2. MLM

    A Rolls with an American engine in it?! I’d drive it. Engine parts would be cheaper,the best of both worlds.

    Like 15
  3. Dave in Arlington, TX

    It seems weird that the builders would go to the trouble of swapping in a LS engine and automatic, but they wouldn’t install A/C. Especially in Texas. Looks like a nice combination otherwise.

    Like 24
  4. MoragaPulsar

    Humm. Doesn’t this car have an integrated hydraulic system that powers brakes, steering and ride height control? How is this handled here? and no A/C? In Texas? Half baked project maybe? no judgements, it looks like a very tough swap. But the lights work as noted on eBay, so there is that. And don’t forget that TrueCoat.

    Like 8
    • Quidditas

      Suspension courtesy of the famed Citroen DS as are the rest of the hydraulics. Nothing that can’t be handled by a competent mechanic with earthmoving equipment experience.

      The engines are very reliable. My late dad had six clients who had this same model and he kept them on the road for decades. My brother now looks after them. I saw an engine stripped and they really are very simple and real quality engineering. As a teenager I helped my father re-veneering a dashboard and door caps – no problem for a violin maker.

      As a Citroen specialist, my dad had these down pat and loved to work on them. Two of them are used as daily drivers by the grandsons and have clocked up over 400 000 miles each but still look pristine.

      On my bucket list – but while excellent not a patch on the DS or SM when it comes to ride. Great, stately motor cars even with the original engine that can be gasflowed together with reground cams to deliver some 25% to 30% more power. Who needs a LS engine?

      Like 17
      • Dave

        I could just imagine the looks on the employees faces as I drive up to the local Cleveland Brothers garage…

        Like 2
      • JoeNYWF64

        Dave, how bout if you drove into a ROLLS DEALER with this car for an oil change, or better yet, with the Ford LTD Rolls station wagon on this site earlier. lol

        Like 1
  5. JoeNYWF64

    I find it hard to believe the torque is so low on a RR 412 cube motor.
    A ’74 pontiac 8 to 1 compress 400 v8 puts out 330 ft lbs at 2800 rpm.
    & its 225 hp was underrated.

    Like 8
    • JudoJohn

      I’ll bet it was actually higher. maybe understated for insurance companies.

      Like 3
  6. Steve Clinton

    “LS Aluminum 6.0 stage 2 cam dod delete arp hardware”
    I’m not a mechanic so can someone translate this?

    Like 1

      I will try
      LS Aluminum 6.0 – Aluminum block as opposed to cast iron
      stage 2 cam – Some performance cam
      dod delete – Displacement on demand – Chevy’s horrible cylinder deactivation system – done for fuel economy but wipes out cams.
      arp hardware – Good nuts and bolts

      Like 11
  7. Will Irby

    The LS is an “ugly engine compared to the original one”? Really? Is there even an engine under all that plumbing in the original picture?

    Like 2
  8. JoeNYWF64

    I’m not sure if the 6L80E trans in the Rolls now is as stout as the turbo 400 that was in the Rolls originally. Remember – this is a VERY heavy car!! Anyone know if the turbo-400 that was in the rolls was the one that bolts up to a chevy v8 or to a Buick/Olds/Pont v8?
    I prefer very long stroke motors like the chevy big block or any of the big inch BOP motors that produce max torque of at least 330 ft lbs at 2000 LOWER rpm than the LS. Plus, unlike the LS, the older motors can accomodate the HUGE harrison a/c compressor to make SURE the distinguished person in the back seat is cool beyond expectations. & i’m sure that person could afford to maintain the system with R12. lol

    Like 2
  9. Chris Webster

    There’s been a couple of ‘cheap’ Silver Shadows for sale near me. I sometimes wonder about an LS swap, ditching the RR suspension for plain coils and simplify the brake system. And ditch the stock steering wheel that belongs on a bus. And a T bar.

    Like 1
  10. Craig

    I’m not sure the engine was the problem. it’s the steering, suspension, and brakes that keep me from being an owner.

    should have just put a 5 or 6 speed behind the original engine.

    Like 2
  11. Jt Toy

    regarding interior shots, scroll down the EBay page to view a video that gives a decent shot of interior, front and rear. The video could have been better, but the interior looks good.

    Like 3
  12. Bob the ICE-man

    Am I wrong? No A.C.! I cannot believe a R/R of this year was originally delivered without A.C.. Concurrent with the engine swap they must have stripped the A.C. System off. I don’t care if the compressor and/or components were shot, the ducting, controls and tubing should enable reinstallation for a couple thousand bucks. If the system was entirely removed, all electrical pulled out it will cost a heck of a lot more to put an entire system in. R/R without A.C. Is definitely a negative item.

    Like 4
    • Bill McCoskey Bill McCoskey Member


      These cars have twin HVAC blower motors on either side of the engine, at the top of the firewall. They direct air thru ducting into the inside of the passenger compartment. All of that air ducting and the blower assemblies have been removed, and a light colored [vinyl] panel installed. This is easy to see in the photos. Unless major changes have been made to the ducting for the HVAC, it’s not going to be operational.

      My memory of the underdash areas behind the metal backing of the fascia, is there is almost no room for changes to air ducting, as that takes up too much room, hence the factory designs had the ducting and blowers in the engine compartment, and well insulated.

      If all they did was remove everything that was in the way of the engine swap, not only will there be no A/C cooling air, but the same ducting also handles the heating system, so there is no ducting for heated air. Then again, there is probably no external fresh air ventilation either.

      I have a good friend who has a beautiful Rolls-Royce Flying Spur with the factory twin turbo engine. It’s done over 150,000 miles, yet because it’s had all of it’s service needs taken care of on time, the car really does look, sound, and operate, like it’s brand new. It’s a totally stock car, very reliable, and I would bet it’s still gonna be faster in the 1/4 mile than this converted Shadow.

      So it appears to me that this car was created simply to show the engine swap can be done. But now what do you do with it?

      Like 2
  13. Gary Rhodes

    In the early 70’s my dad’s lifelong friend had a 37 Silver Wraith? They were hot rodders in the fifties and he was going to hot rod it. A really pretty car with flowing lines. He contacted RR about the grill slats as they were inop. They said five people in the world knew how to work on them and they all worked at RR. They asked about his plans and he told them a 427 Chevy and auto. They said he couldn’t do that to one of their cars and he said “Watch me”. It was a really nice car when it was done

    Like 1
  14. Bill McCoskey Bill McCoskey Member

    As someone who has had multiple Shadow cars, 1967 to 1975, I would be very concerned about the brakes and suspension, as well as the air conditioning.

    These cars were equipped with a high pressure hydraulic system [2,500psi] that supplied brake fluid and suspension hydraulics. The pumps were integral with the motor. So how have they dealt with the breaking and suspension systems since this engine change? The brakes were massive [4 calipers on the front] as the car was almost 3 tons in weight.

    It appears from looking at the underhood area, that the air conditioning has been removed, so the buyer should check the A/C too, as the car is being sold without warranty of any kind.

    Like 1
    • Quidditas

      The hydraulic pump is driven off an auxiliary belt. But that engine bay is so cavernous that an electric pump and combined hardware and software from a 2003 or later Citroen C5 could be fitted unobtrusively as there is so much space in that engine bay.

  15. Gerard Frederick

    Dear Laurence – thank you for your input. You are right, sometimes I get carried away which of course means I´ll be wrong and for that I apoloigize. I cannot reply to you in detail since that would violate the forum´s (very wise) rules. I didn´t want to be flippant and realize of course that my remarks apropos the Blitz were insensitive. As far as my criticism of english cars and motorcycles goes I have in depth experience with British cars having owned one MG, 2 Triumph TR3´s and a Jag XKE roadster. One of my army buddies had a 1960 Bugeye Sprite which to this day is one of my favorite cars, just great fun, easy to work on and an ingenious example of engineering. My favorite British bike is the 1955 Panther M 100 and frankly I miss the hell out of my 1959 Triumph TR3, Lucas electrics notwithstanding, oh and I owned two British Garrard turntables – one with dual tone arms – and Wharfdale speakers, back in the day. Now please open a bottle of Foster´s Lager and chill out! your buddy Gerard

  16. Jim in FL Member

    No A/C? No Sale!

  17. Andreas Winter

    Generally I have a problem when a car is fitted a non original engine. In Germany where I live they won’t give you a classic tag for the car. I agree that the problem with the Rolls Royce engine was probably that it sat too long. In the UK you can get a decent spare engine (used) for around 2000pounds. Even though that engine is not too powerful it develops it’s max torque at 1500 rpm. I’m not sure if the replacement engine has the same characteristics.

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