When Belgian engineer Zora Arkus Duntov made a trip to Sebring in 1956 with several Corvettes to contest the 12-hour endurance race, the results were… well, spotty at best. What did end up being quite successful was the testing and release of several competition-proven components for the 1957 model year.

These were packaged as a rather expensive “Heavy Duty Racing Suspension” option, for which only 51 buyers put up the $780.10 premium. Compared to the $3176 base price of the car, RPO 684, as it was known, bumped the cost of a car by almost 25%. In addition to heavy-duty springs and shocks, an RPO 684-equipped car also received finned brake drums with cerametallix linings, vented backing plates and cooling scoops for the rear brakes.

When combined with RPO 579, as is the case for this 1957 Corvette, the addition of a 283 CI fuel injected V8 engine made for a potent track car.

With its BorgWarner T-10, 4-speed manual transmission and posi-traction rear end, as well as options of a soft top only and radio delete, it is self evident that this car was ordered with one use in mind – competition. Whether it actually did take to the pavement in anger is not documented in its listing for the Barrett-Jackson Collector Car auction.

Offered to collectors with no reserve bid, the car closed out the action with a final tally of $95,700, which includes the buyer’s commission. While a car this unique would not be expected to return to all out competition, we can hope to perhaps see it some day in a historic racing event. There is no doubt that a well equipped car like this one would be quite an experience, were it to return to Sebring, for example.