With 320 hp and a slightly better power/weight ratio, the DeSoto Adventurer was a worthy challenger to the mighty Chrysler 300B.

In 1955-56, the Chrysler Corporation brands took a new and sudden interest in the performance market with the Chrysler C300 and 300B, the Dodge D-500, and the Plymouth Fury.  On February 18, 1956, DeSoto, too, joined in with the Adventurer. Based on the top-of-the-line Fireflite two-door hardtop, the limited-edition, mid-year  model took its name from a pair of recent DeSoto dream cars, the Adventurer I and Adventurer II.

White the Adventurer sported a number of distinctive features, its soul was the specially tuned engine, a joint project of the DeSoto division and Chrysler Central Engineering. DeSoto already had one of the more  powerful V8s on the market in the Fireflite’s standard hemi V8 with 330.4 cubic inches and 255 hp. The Adventurer’s V8 received a little more than the usual warming over.

First came a .060-inch overbore, more than feasible with the standard DeSoto block casting, increasing the displacement to 341.4 cubic inches. A more aggressive camshaft with .431-in intake valve lift, .413-in exhaust, and 280 degrees of duration was slipped in, while high-domed pistons boosted the compression ratio from 8.5:1 to 9.25:1. On top was a 2×4 intake manifold with a pair of Carter WCFB carburetors, dressed out with a batwing air cleaner assembly with inverted filters for hood clearance. Meanwhile, a heavy-duty crankshaft and connecting rods kept everything together. The package received an impressive yet conservative rating of 320 SAE gross horsepower at 5,200 RPM and 365 lb-ft of torque at 4,000 RPM.

One early demonstration of the combination’s muscle came at the Pikes Peak Hill Climb on July 4, 1956, where the Adventurer pace car could reportedly top 100 mph on the straight sections. But earlier that year at Daytona Beach, a prototype with the Adventurer V8 and Red Byron behind the wheel ran 137 mph, and this same car later ran 144 mph on the big oval at Chrysler’s Chelsea, Michigan Proving Grounds.

Gold was the theme of the Adventurer’s visual presentation: multicolor exterior paint combinations based on Adventurer Gold, gold and brown upholstery and gold flecks in the carpeting, and anodized gold wheel covers shared with the limited-edition DeSoto Indy 500 Pacesetter. Some marketing materials (see below) touted the car as the “golden Adventurer.” Priced at $3,728, a premium of $382 over the Fireflite coupe, the Adventurer sold out its limited 1956 production run of 996 cars in just a few weeks, reportedly.

The Adventurer continued on the same course for 1957, with the displacement increased to 345 CID and the output rating boosted to 345 hp—the magical one horsepower per cubic inch. But in successive years, the Adventurer’s performance image and specs were progresively watered down. In 1959, the Adventurer V8 became available in all DeSotos, and for 1960, the Adventurer was simply the top trim level above the Fireflite. For MY 1961, there was no Adventurer, only a single model, DeSoto, and on November 30, 1960, the division was shut down for good.