Mopar Engine I.D.

RB CHRYLER Big Blocks

383 "RB" Engine

1959-60 • 4.03" bore x 3.75" stroke
This engine seems to be a greater point of confusion than any other engine. The 383 in this form is an "RB" engine (not the common 383 "B" engine). The 383 "RB" was only found in the Chrysler division car line from 1959-60 (in the Windsor and Saratoga models). Both a 2-bbl and 4-bbl existed with the 4-bbl making 325 hp. With only 2 years of production, these engines are quite rare today.

413 "RB" Engine

1959-65 • 4.18" bore x 3.75" stroke
By raising the deck height of the B engine (hence the RB, or "Raised B" designation), Chrysler was able to increase the stroke on their big blocks to 3.75", resulting in the 413 (when combined with a 4.18" bore). Initially only available in Chrysler division cars, Dodge and Plymouth got it in 1961. In 1962 the 413 Max Wedge was introduced and in the capable hands of racers like Dick Landy, the 413 was breaking records all over the country. Through fine-tuning and careful modification, Super Stock racers of the day were making upwards of 450 rear-wheel horsepower with the Max Wedge.

426 "RB" Engine

1963-65 • 4.25" bore x 3.75" stroke
By 1963, both Ford and GM had 420+ cubic-inch engines on the streets and race tracks of America. Obviously Chrysler had to keep up, and did so by opening the 413's bore to 4.25", thus creating the 426 Max Wedge. In its initial form, the 426 was only slightly more powerful (rated at 425 horsepower) than the 413 it replaced. But with the release of the Stage III 426 Max Wedge in 1964, all comparisons to the 413 ended. The '64 Max Wedge sported a lofty 13.0:1 compression ratio, a longer-duration cam, larger carbs and an elaborate equal-length "Tri-Y" exhaust manifold setup. The street 426 used a single 4-bbl, 10.5 compression ratio and a milder camshaft. While it obviously made less power than its Max Wedge brother, it was much more livable.

440 "RB" Engine

1966-78 • 4.32" bore x 3.75" stroke
If there's one golden rule of '60s engine design, it's simply bigger is better. Thus, the 440 cubic inch RB engine was born. Although debuting at a stout 365 horsepower in top form, the 440 was overshadowed by the Street Hemi which was released in the same year. But it didn't take long for the 440 to make a name for itself. In 1969-70, the 440 reached its highest state of tune with the fabled 6-bbl version rated at 390 hp. This number declined slightly in 1971 to 385 hp, which was the last year for the 3x2-bbl option. The 440 remained in production until 1978, although by then it had been strangled by the same unleaded fuel and emissions monster that ultimately killed all of Detroit's big blocks. But the fact remains that, at least on the street, the hot-rod 440 six bbl. engines of the '69-70 period would often humble a similar Hemi-equipped model.