Disclosure: This site may receive compensation when you click on some links and make purchases.

Cadillac Powered: 1948 Buick Super Convertible

This great-looking 1948 Buick Super Convertible has a bit of a surprise under the hood, it’s currently equipped with a big-block Cadillac engine! These cars have been in demand since Rain Man, but at least this one is not a 100-point restoration that will go to some wealthy collector for six figures. It’s slightly ragged but right, and not so perfect you’d be afraid to take it out for a Sunday cruise. You can find it here on eBay in Leander, Texas.

The Rain Man car was a 1949 Roadmaster. The bid for this Super is around $20,000, but not surprisingly the reserve hasn’t been met. New on this car are the gas tank, the fuel lines and pump, the carb, and the water pump. It’s got an automatic transmission and power windows. The seller thinks it’s wearing the original yellow paint, and claims that it has “almost no rust” with solid floorboards and panels. There are some extra parts, including the original radio. The top is in good condition, though we don’t see it up, with a functional hydraulic pump. The interior is seen at a distance, but the seller likes the word “solid” and that’s his word for the interior, body, and in fact the whole car.

This car looks like a driver, for people who don’t care whether the interior is 100 percent original or the chrome is mirror perfect. What needs doing? “Some TLC to make a daily driver,” including a fan clutch and a power-steering pump. So it’s got power steering, an advantage in one of these big old boats. An engine shot would have been useful—we don’t know the age of that Caddy big block. Personally, if I was selling this car I’d show off that motor.

The Super was in the middle of the range, below the four-porthole Roadmaster, and was sold as a coupe, sedan, convertible, and station wagon. It sat on a 125-inch wheelbase (four inches short of that Roadmaster). The standard engine was a 248-cubic-inch Fireball Straight Eight that made 115 horsepower (five more than the Special, thanks to an altered compression ratio). The Roadmaster’s 320-cubic-inch version increased the ante to 144 horsepower.

The second-generation Super was introduced in 1942 and lasted until 1948. The standard transmission was a column-mounted three-speed manual, but the Dynaflow automatic was optional. Presumably, this car has one of those, or maybe a more modern tranny that marries to the Cadillac engine. I’m noticing what appears to be a modern GM steering column.

The Classic.com price for a second-generation Buick Super is $48,000, and convertibles and woodies command a premium, obviously. It would pay to watch this listing as it moves through the system. What a fun car this would be to own!


  1. Avatar photo 8banger Member

    Screaming Yellow Zonkers!

    Like 4
  2. Avatar photo Rex Kahrs Member

    I’m and excellent driver.

    Like 6
    • Avatar photo Aussie Dave Member

      Lol, you beat me to it.

      Like 4
  3. Avatar photo Rex Kahrs Member

    Well, allrighty then!

    Like 4
  4. Avatar photo Aussie Dave Member

    I love the look, love the lines, I would have been in my element if I was born 20 years earlier.
    I can live with the imperfections, but not the caddie motor. Any correct date Buick motor would have been better.
    That’s all I would change.

    Like 14
    • Avatar photo Garry

      I agree Dave, put as close as possible to an original straight 8 back into it!

      Better a Urin8 than a V8

      Like 2
  5. Avatar photo bobhess Member

    They sure knew how to put style into their cars in those days. Rex, you forgot your hand fed pigskin driving gloves…

    Like 4
  6. Avatar photo Terry

    The rear fender chrome housed mounted reflectors always did it for me, remember looking at em when my dad would wash our new 47 (black) Super sedanette in the day. And agree, cars were styled for the times to, the art seemed to fade by the mid 70s. Yes, the straight 8s were long, just like the half mile long 6 volt batteries used in the Buicks.

    Like 7
  7. Avatar photo JustPassinThru

    A lot of questions unanswered. Was it a 6 or a straight-8 originally? The wheelbase was longer with the long 8

    What happened to the original mill? Especially an in-line 8, would have been quite the conversation starter.

    With the modern steering wheel and column, may include other modern parts. Is the power steering original, or with the engine, transmission and column?

    Like 1
    • Avatar photo Tony Catania

      There Wasn’t Any 6 Cylinder Buick Engines Till The 1961 Special Compact Series Was Introduced All Buicks Were 8 Cylinder Vehicles. Back When This Car Was Made.

      Like 6
      • Avatar photo JustPassinThru

        I only know what I read. This was about ten years before my time, and I’ve only seen one in a distance.

        But I got curious about the Eight – which I was sure was in-line. Turns out, according to Wikipedia, there were both sixes and eights.


        “When the Series 40 was introduced, it had the 257.5 cu in (4,220 cc) overhead valve Buick Straight-6 engine that produced 80.5 bhp of power at 2,800 rpm, and 74,257 examples were made, being the highest number of Buicks for 1930. For the year 1931, the Series 40 was temporarily discontinued, with the introduction of the Marquette Model 30 and the Series 50 being repositioned as the Buick entry level product.[2] The 1935 version returned with the 233.0 cu in (3,818 cc) Buick Straight-8 engine and 93 bhp. Starting with this generation, all GM cars shared a corporate appearance as a result of the Art and Color Section headed by Harley Earl and modest yearly changes were introduced to freshen the appearance.”

        Like 0
      • Avatar photo JustPassinThru

        Okay, I see now that was the prewar Special.

        My mistake…as the hedgehog said, after embracing the toilet brush…

        Like 0
      • Avatar photo Gil Davis Tercenio


        The Series 40 received the name “Special” in 1935 and it was a straight eight. As noted, the V6 appeared in the 1960s. It was later to appear in Jeeps and then was bought back by GM when gas mileage became a big selling point.

        Like 0
    • Avatar photo Gil Davis Tercenio

      Buick went from their OHV straight six engines to building straight eights only in 1931. Their first V8 appeared in 1953, in the Super, Roadmaster and Skylark. The ’53 Special was the last of the straight eights.

      As noted, a six cylinder didn’t reappear until the early 1960s.

      Like 2
  8. Avatar photo Rw

    Who knows what’s under the hood?? No pics it might have a Northstar…

    Like 5
    • Avatar photo Doug7488

      I’m curious as to what the car has for rear axle and suspension- assuming they did away with the torque tube rear

      Like 1
  9. Avatar photo Christopher Gush

    Well I imagine somewhere along the line its former owner decided the inline Fireball Eight was insufficient to propel this “Lead Sled” along.., thus the conversion. Interesting to note limited photos.??

    Like 0
  10. Avatar photo Chris Cornetto

    I like it, as it went from, ” Scotty I need that power!” To, “You’ve got it Captain”. I had a 49, a 472/500 with a 400 th and a 73 and up pick up truck rear, if that’s what this has makes this a easy daily rider. I still have a 58 wagon and that Dynaflow torque tube marvel can be a hell on earth.

    Like 3
    • Avatar photo Doug7488

      Did you use the C10 bars to locate the rear?
      That’s what I’m up against now on my 48

      Like 0
  11. Avatar photo Nelson C

    There used to be a couple who would show up to the Cohoctah July 4th parade with one of these. Beautiful car their s was. He said the fire ball eight was happiest at 45 mph with the 5.13 gear.

    Like 1
  12. Avatar photo Mike's57

    Interesting car, sketchy eBay listing… Hidden feedback is a RED flag to me. Why no pictures of the engine? $27K and that’s all the info provided???

    Like 2
  13. Avatar photo Al Dee

    What’s with that modern steering wheel and steering column with its column ignition??? To me – that ruins the car and drops its value considerably as it would cost a lot to take it back to original, which also implies there’s most likely other non-original modern stuff in it, which makes it nothing more than a shell of a ’48 Buick – not worth anything near a classic price. It’s unfortunate for those who already have a BIG bucks bid in the auction – no way to back out now – a teaching moment for all: “Know what you’re buying” before putting your money down.

    Like 3
  14. Avatar photo MarkyMark

    When I see one of these I recall my dad telling a story about him and his best buddy (my godfather) who owned one in the early 50’s racing some guys with the top down going well over 100 mph. My godfather was a gear head, had a big block ‘68 Corvette with a blower, and had a GTO, ‘74 Trans Am Super Duty, and ‘87 Grand National as daily drivers over the years.

    Like 2
    • Avatar photo Gil Davis Tercenio

      My first car was a ’52 Buick Super 4D, 263 straight eight and Dynaflow transmission. I once had it up to 103 MPH, with three passengers onboard.

      Like 0
  15. Avatar photo Mark

    Dad lets me drive slow on the driveway

    Like 2
  16. Avatar photo George

    TONS of laughs driving one of these, a 4 door version that belonged to a friends dad. The rear shocks were gone and if you stopped fast at a stoplight it would bounce up and down to the amusement of the occupants in the car beside us. Actually more amusing to us as goofy teenagers.

    Like 1

Leave A Comment

RULES: No profanity, politics, or personal attacks.

Become a member to add images to your comments.


Get new comment updates via email. Or subscribe without commenting.