The long and glorious story of the big-block Chevy starts here, with the 1965 396 V8.
The Chevrolet 396 cubic-inch V8 was introduced in January of 1965, midway through the ’65 model year, but maybe the proper place to begin is with the near-legendary 427 NASCAR Mystery engine of 1963. (See our feature on the mystery engine here.) Although the 427 Mystery Mark II V8 and the 396 Mark IV are of two different engine families, they are products of the same development path and share many of the same features. But while the Mystery engine effectively dead-ended in ’63, the 396 was the first in a long and successful series of big-block V8s, opening a chapter in the Chevy performance story that is still being written.
The most obvious element of the Mystery engine that was carried forward to the 396, and all the big-block Chevy V8s that followed, was the distinctive canted-valve cylinder head, above. By splaying the intake and exhaust valves relative to each cylinder, the valve diameters could be larger and the port angles straighter, improving airflow. With the valve covers removed, the valves and rocker arms on this novel setup appeared to be pointed in every direction, inspiring the nickname “porcupine head” early on. At some point the engine family picked up the name big-block due to its larger bore spacing and taller deck height than the original 1955 Chevy V8, aka small-block.
There were actually three 396 cubic-inch V8s introduced in early 1965, including the L78 for the Corvette and full-sized cars and the L37 for a special version of the Chevelle SS known as the Z16. All featured a 4.094-in bore and a 3.760-in stroke and were marketed under the name Turbo-Jet V8. Rated at 425 hp at 6400 rpm, the L78 was a serious piece of equipment, boasting four-bolt main caps, a Holley four-barrel carb, an 11.0:1 compression ratio, and a solid-lifter camshaft.
The L37 V8 for the Z16 Chevelle was essentially the same stout package but with a less aggressive camshaft profile and hydraulic lifters, and it earned a 375 hp rating. The 396 in the Z16, an extensively equipped machine, was dressed out with a chrome air cleaner lid and valve covers. (Only 201 were built.) Finally, there was an L35 version in milder tune for the big cars (Biscayne, Bel Air, Impala) with a 10.25:1 compression ratio and 325 hp.
Introduced at mid-year, the ’65 396 was not produced in massive numbers, but it spawned an extensive line of 396 and 427 CID V8s for 1966 and beyond. A 454 CID version appeared in 1970, and in its final state of production development decades later, the big-block V8 evolved into the 8.1 liter (496 CID) Vortec used in Chevy trucks n 2001 through 2006. But the story hasn’t ended yet.
Chevrolet Performance continues to produce and market the engines along with a complete line of parts. For proof of concept of the original Chevy big-block design, the ultimate in the catalog is a 632 cubic-inch crate engine—available straight over the counter—with 1004 hp and 876 lb-ft of torque. And it all began with the 396 V8.
The 396/375HP was one mean street machine. A local Chevelle routinely thumped the two local Hemi Roadrunners.
There was a rumor that the 396 was actually 405 CI. Any truth to that?
From mid-1969 to 1972, the 396 was actually 402 CID, as the bore was increased slightly. The 396 designation was retained for branding purposes and to avoid confusion with the 400 small-block V8.
My ’71 Chevelle wagon came factory with a 402-300 and “400” fender emblems. I thought the car had a small-block 400 in it when I first saw it. Opening the hood for the first time was a pleasant surprise!
Truck engine,, or at least big car engine as they are quite heavy. As has been proven time after time a Camaro is generally faster [on a roadcourse] with a small block as it handles better and the ability to be revved harder.
396 in particular as it really makes little more power [but more torque] than 327 or 350. 427 454 is a different thing as they can and do make far more power. But still way too heavy.