Curbside Classic: 1968 Chevmobile Impala 455 – A Hybrid Of A Different Sort

(first posted 2/29/2012)    Hybrids are very big in Eugene, but some are just plain huge. The Prius has become the official car of Eugene, having dethroned Subaru. But here’s a hybrid of a different color: instead of a marriage of two drive systems, it’s a cross between two brands, the engine of one transplanted into another. Back in the day, when these were popular, the goal was speed, not better mileage (well, usually). And the resulting names of these cross-species hybrids were more colorful than Prius or Insight: Fordillac, Studillac, Fordick, Fordolet. Well, here’s a new one: a Chevmobile.


Lift up this Impala’s half-acre slab of hood, and where you might expect to encounter the ubiquitous small block, or perhaps a rat motor, sits an Olds 455. There’s nothing to give that surprise away, from the outside, so fortunately its owner came out to show off his beastly mongrel.


Looking at these pictures now, I see that the badge next to the front side-marker light that normally announces the engine size to the inquiring world is missing. Did he take it off purposely, to arouse suspicion, or to not mislead the unwary; or did this car start life as a fairly rare six-cylinder Impala hardtop coupe, one of a few thousand built that year?

Lost in surprise and admiration of that clean Olds V8, I forgot to ask him what exactly inspired this cross-divisional heart transplant. It’s not like big-block Chevys are hard to come by. Whatever; I love it. And it’s so utterly antithetical; Chevy engines have been the overwhelming choice of engine transplants into other makes since the first small block coughed to life in 1955. But then the big Olds has many compelling features, not the least of which is its relatively light weight and high quality.


This car brings back a flood of memories wasting hours at the drug store poring over various hot rod magazines in the sixties. Engine transplants are as old as the Model T, and kids are still dropping Integra VVT engines into Civics; but I’d say the golden age was the fifties and sixties. By that, I mean the randomness of the transplants. By the seventies, the Chevy V8 was such a dominant and universal transplantee, it got rather predictable and boring. But previously, anything went anywhere, as long as the new engine made more power, and a stout oak tree, a chain, and a come-along were handy.



There are two main eras to indulge our engine-swapping nostalgia with: pre and post OHV V8. Just to clarify, we’re talking about cross-brand swapping; dropping Ford’s flathead V8 into old Ford rails is a different category; let’s call that “updating”: expedient and cheap, but not as original or creative. In the pre-OHV V8 era, I’m thinking particularly of the Chevy and GMC sixes, and the Buick straight eight (above).


The Ford V8 is a legend, and we’ll find one to honor here, but the flathead design had serious intrinsic faults. That drove quite a few to plumb the performance possibilities of the OHV GM units. Contrary to the myth of the Ford being the ubiquitous hot rod engine in the forties and fifties, there was a strong Chevy stove-bolt and Jimmy contingent. A full range of after-market speed parts were available, and with their intrinsically superior breathing and thermodynamics, they put in a strong showing at the drags and Bonneville.


The big Jimmy sixes, with 270 and 302 cubic inches, were brutes, and with modified cylinder heads and five carbs like this example, they flew, as in right past a flathead Ford.


And the big, long Buick straight eight had a powerful presence too, both visual and aural. Check out this one with four SU carbs! That’s from the days when not every rail had a blown Chrysler hemi in it. The rat rod scene is doing its part to revive the use of oddball engines; old sixes and straight eights are in demand again.


When the Caddy V8 appeared in 1949, it might as well have been the second coming. Two visionaries, Bill Frick and Phil Walters, quickly made a business case out of it by dropping brand-new 331 Caddy engines into the light Ford sedans for a thousand bucks. The resulting hybrid was dubbed Fordillac, and made quite a sensation. “Uncle Tom” McCahill loved it, and it caught the eye of Briggs Cunningham.


Cunningham would have taken one to race at LeMans, but the rules wouldn’t allow it. But he did hire Frick and Walters to run his Caddy racing program, which we covered in our story of the hot-rod ’50 Caddy. And when the super-low ’53 Studebaker Starlight coupe appeared, Frick and Walters were on it in a flash, creating the legendary Studillac. Here is a review by McCahill of this 125 mph coupe that could outrun pretty much anything on both sides of the Atlantic at the time.

Lest I get accused again of slighting the Olds Rocket V8, it too was popular from its arrival six months after the Caddy. But obviously, plucking new engines from the assembly line was not cheap. But as soon as they started showing up in junkyards, shade-tree transplantists were all over them. And until the Chevy V8 started filtering down, big Caddy, Olds, nail-head Buicks, and Chrysler hemis were the implants of choice.



All this distraction about hybrids, and I haven’t even started on the ’68 Impala itself. The ’68 marked the end of the fastback, and the beginning of the post-283 era. The standard V8 was now the 307, for one year only. Of course, during this golden era, just about every engine in Chevy’s vast arsenal was optional, right up to the 425hp 427 (7 liter) big block. The sleeper of the bunch was a 3500lb Biscayne two-door, with the hot 425/427.


But then this Chevmobile’s motor looks pretty warm too: Edelbrock intake supporting a big four-barrel, tube headers, probably a hot cam. And it makes nice music, when I hear it from time to time on the streets near the campus, mixing it up with all the other silent hybrids.