by Bob Doty

Mopar Big Blocks, Part Two

The last installment dealt with the low-deck engines and the natural progression of the displacement variations. This time we will talk about the raised block versions of the big block Mopar. The 413 wedge was first introduced in 1959 in the Chrysler nameplate and 1961 in the Plymouth and Dodge lines. The bore and stroke measured 4.180 x 3.750. The engine was rated at 350 horsepower at 4600 RPM and 470 ft. pounds of torque at only 260O RPM. The long ram version produced 375 horsepower at 5000 RPM and 465 ft. pounds of torque at 2800 RPM. The higher horsepower was at the expense of low end torque.

1962 was the year that stands out in the minds of true performance enthusiasts. Described to this day as the Magnificent Max Wedge, the 413 Max Wedge motor raised the bar for performance. Truly a drag strip only creation, this engine featured the following significant parts:

* Unique heads with 25% larger intake and exhaust ports
* No heat crossover
* 2.08 intake valves and 1.88 exhaust valve size
* 510 lift mechanical camshaft with 300 degree duration
* Special tubular pushrods
* Dual valve springs-and nodular iron adjustable rockers
* One piece ram induction manifold with 15 inch runners
* Staggered dual Carter AFBs with 650 cfm each (3447)
* 11.0 or 13.5 TRW forged pistons
* Forged and magnafluxed rods
* Cast iron headers
* Deep grove pulleys
* Special baffled oil pan and custom swinging pickup

The 1962 Melrose Missile was the first production passenger car with a factory option engine into the 11's. Tom Grove ran an 11.93 @ 118.57 on July 15th, 1962.

The Max Wedge 413 was dropped in 1963, but the 413 displacement engine soldiered on until 1965 in the Chrysler models. A dual four barrel version was available throughout 1964.

The 426 wedge engine also appeared in 1962, but was only installed in the top of tile line Chrysler models. The Dodge and Plymouth debut was saved for 1963 and it was special, the Max Wedge 426, Stage II. The primary difference was in the bore... which was enlarged to 4.25 inches. While the books show that the Stage III engine was not introduced until the 1964 model year, this is not entirely true, based on my own personal experience. The Stage III appears to have been available in late 1963. The Carter AFBs were changed to the 3705 number and offered a higher CFM rating. The basic difference is that the 3447s have four venturis with the same size, or 4 equal holes in each carb mounting flange. The 3705ís feature larger secondaries, with tile original size primaries. It does appear to be a common performance improvement for the Stage II engines to have the carb mounting flange enlarged to accept the larger carbs. The camshaft was increased to 520 lift and 320 degrees of duration on the Stage III engines. There was a new cast iron header offered which was referred to as the Tri-Y.

The street wedge was offered in 1964 and 1965, rated at 365 horsepower and 470 ft. pounds of torque. It was a single four barrel engine of conventional design and street application.

1966 found the 440 cubic inch engine offered in the big car passenger line. The engine was offered in two versions: 350 horsepower @ 4400 RPM and 365 horsepower @ 4600 RPM. Both engines developed 480 ft. pounds of torque. Neither engine was considered a performance engine. With a bore of 4.320 and the long 3.73 stroke, the performance image of the largest displacement engine ever installed in a Chrysler Corp. vehicle was about to change. The Super Commando, Magnum, and TNT pieplates were installed in 1967. The high lift cam, modified exhaust manifolds, hi-flow closed chambered heads, increased exhaust valve size, dual exhaust and the R/T & GTX nameplates spelled trouble for the competition. 375 horsepower @ 4600 RPM and 480 ft. pounds of torque at 3200 RPM. Chrysler had a winner. The 440 high performance engine fit very nicely between the 383 and the 426 hemi. With the addition of the 6-pack induction in mid 1969, and the 390 horsepower rating, the 440 with the right gearing was nipping at the heels of the hemi. By 1971, the 440 was beginning to suffer from emissions, mileage, and other corporate ailments. The 1972 brochure does show the 6-pack option, but few, if any, were produced. The engine stayed in production until 1978, and the last 440 was offered in trucks and motorhomes.

Recently, one of the Mopar magazines asked the trivia question... Which engine has been produced in the most displacement sizes, the low deck or raised block? The correct answer is the same number. Tile low deck variants have been the 350, 361, 383, and 400. The raised block... 383, 413, 426, and 440. The raised block 383 is basically non-existent, but was built.

This article appeared originally in the September, 1997 Mopar Muscle Club of San Antonio, Texas Newsletter.
It is used here with permission of Bob Doty.

November 8, 1997

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