by Wild About Cars staff, reprint with permission only 

1965-1969 396
The 396 cubic inch version of the big-block was available from 1965-1969. The first 396 was available in the 1965 Corvette. It was designated as option L78, and it was rated at 425 HP at 6,400 rpm, with 415 foot-pounds of torque at 4,000 rpm.

• 1965 L78 396. The L78 came with the large-port cylinder heads, with 2.19" intake and 1.72" exhaust valves, and 11.0:1 compression ratio. It utilized a four-bolt-main engine block, forged-steel crankshaft, a solid-lifter camshaft, and an aluminum high-rise-type intake manifold with a Holley four-barrel carburetor. All L78s produced during 1966-1969 used a solid-lifter camshaft.
  
  
• 1965 Z16 Chevelle 396. The same engine, as installed in the Z16 Chevelle, was rated at 375 HP, the only change was that it was equipped with a hydraulic-lifter camshaft.
  
  
• 1966-69 L78 396. The L78 was essentially the Corvette's introductory big block. It came with the large-port cylinder heads, with 2.19" intake and 1.72" exhaust valves, and 11.0:1 compression ratio. It utilized a four-bolt-main engine block, forged-steel crankshaft, a solid lifter camshaft, and an aluminum high-rise-type intake manifold with a Holley four-barrel carburetor, rated at 375 HP.
  
  
• 1966-69 L34 396.In 1966, the medium-performance L34 396 cubic inch engine still was equipped with the four-bolt-main block, however a cast-iron crankshaft, smaller-port cylinder heads, and 10.25:1 compression ratio pistons. It featured a higher lift hydraulic-lifter camshaft, cast-iron intake manifold, and Holley four-barrel carburetor. It was rated at 360 HP. From 1967 to 1969 the L34 was rated at 360 HP at the same rpm.
  
  
• 1967-1969 L35. The L35 was the 325 HP 396. It had a two-bolt-main engine block, a cast-iron crankshaft, small-port cylinder heads, 10.25:1 compression ratio, a hydraulic-lifter camshaft, and cast-iron intake manifold with a Rochester Quadrajet carburetor.
  
  
• 1969 LS3. The LS3 396 was optional on the 1969 full-size car line. It was strictly low-performance as it was fitted with a two-barrel carburetor and made 265 HP.

1966-1969 427
The first Mark IV 427 cubic inch engine was delivered on the Corvette and the Chevrolet full-size car line. The 427 had a bore and stroke of 4.251" x 3.76".

• 1966-1969 L36. The standard 427 was designated L36 and it used the two-bolt main-bearing block, forged steel crankshaft, hydraulic camshaft, small-port, small-valve cylinder heads, 10.25:1 compression ratio, with a cast-iron intake manifold (1969 Corvettes received an aluminum unit), and it was fitted with a Rochester Quadrajet carburetor. It was rated at 390 HP. The L36 continued on the Corvette through the 1969 model year. The same engine, but rated at 5 HP less, was used on the full-size car line during 1967-1968, but returned to the 390 HP rating for 1969.
  
  
• 1966-69 L72. In 1966 the more powerful option L72 was released. The L72 had a four-bolt-main engine block, forged crankshaft, large-port, large-valve cylinder heads, 11.0:1 compression ratio, solid-lifter camshaft, and an aluminum intake manifold with a Holley four-barrel carburetor. It was rated at 425 HP. The L72 was available in the Corvette only in 1966. From 1967-1969 it was available in full-size cars.
  
  
• 1967-1969 L68. The L68 version was optional on Corvettes from 1967 to 1969. It was basically an L36 engine with a Tri-Power intake setup. It was rated at 400 HP.
  
  
• 1967-1969 L71. Also available on the 1967-1969 Corvette was the L71 427 cubic inch V-8. It was similar to the 425 HP L72 engine, but it used the Tri-Power intake setup instead of a single four-barrel carburetor. It was rated at 435 HP.
  
  
• 1967-1969 L89. The L89 was the L71 engine equipped with aluminum cylinder heads.
  
  
• 1967-1969 L88. The most powerful 427 cubic inch V-8 was the L88 - though it was rated at 430 HP. It had all the L72 components plus aluminum cylinder heads. It came with an aluminum high-rise intake manifold and a Holley 850-cfm carburetor.
  
  
• 1969 ZL1. The ZL1, available only during 1969 on the Corvette and Camaro, was an all-aluminum 427 cubic inch engine.
  
  
• 1969 LS1. There was another 427 that is far less known - the 1969 LS1. It used the two-bolt-main engine block, small-port, small-valve cylinder heads, 10.25:1 compression ratio, hydraulic camshaft, and cast-iron intake manifold with a Rochester Quadrajet carburetor. It was rated at 335 HP.

1970-1972 402
Increasing the 396's bore to 4.125", resulted in the 402 cubic inch engine. This was done during the 1969 model year, thus both 396 and 402 cubic inch big-blocks were fitted that year.

• 1970 L34, L35, and L78. The power ratings were unchanged from those of the 1969 396. The L34, L35, and L78 continued to be available in 1970.
  
  
• 1970 L89. There was also a limited run of the L78 equipped with aluminum cylinder heads - designated option L89.
  
  
• 1970 LS3. The LS3 option code was also carried over into 1970 and made available on other Chevrolet car lines, including Chevelle. It was marketed as the "Turbo Jet 400", however it now received a 4-bbl carb and was rated at 300 HP. The L34, L35, and L78 were dropped at the end of the 1970 model year.
  
  
• 1971-1972. The LS3 was the only 402 cubic inch engine available in these two years. The LS3 was dropped after the end of the 1972 model year.

1970-1976 454
With a bore of 4.251" and a stroke of 4.00", the 454 cubic inch V-8 was the largest factory-built big-block. Three versions of the engine were released in 1970 - LS4, LS5, and LS6. The 454 would continue to be built from 1970 through 1976.

• 1970 and 1972-1976 LS4. The LS4 was offered on the Chevrolet full-size car line. It was a low-performance engine with the two-bolt-main block, small-port cylinder heads, hydraulic camshaft, and a cast-iron intake manifold with a Rochester Quadrajet carburetor. It was rated at 345 HP at 4,400 rpm, with 500 foot-pounds of torque at 3,000 rpm. The engine was not offered in 1971 but returned in 1972 with an SAE net rating of 270 HP. The LS4 was the only 454 cubic inch big-block available during 1973-1976.
  
  
• 1970-1971 LS5. The LS5 was a medium-performance engine. It used the two-bolt-main engine block, the small-port cylinder heads, a hydraulic camshaft, and a cast-iron intake manifold with a Rochester Quadrajet carburetor. Its power rating depended on which vehicle it was installed in. In the Corvette, it was rated at 390 HP in 1970 and 365 HP in 1971. In the Chevelle it was rated at 360 HP in 1970 and 365 HP in 1971.
  
  
• 1970 LS6. The LS6 was only available on the 1970 Chevelle and on the 1971 Corvette. The engine got the four-bolt-main engine block; the large-port, large-valve cylinder heads; a solid-lifter camshaft; and a low-rise aluminum intake manifold with a Holley four-barrel carburetor. The engine was rated at 450 HP in the Chevelle and 425 HP in the Corvette. The Chevelle version had cast-iron heads, while the Corvette version got aluminum cylinder heads.
  
  
• 1970 LS7. The LS7 was a stillborn engine for the 1970 Corvette. It was listed in factory literature, but the engine was never released. Initially, the engine was to have a Tri-Power intake, rated at 460 HP. Later, it was revised to a single 850-cfm Holley four-barrel carburetor on an aluminum high-rise intake manifold for 465 HP output. In other respects, the LS7 was similar to the LS6 but with a more radical camshaft and open chamber aluminum cylinder heads.
  
  The engine was not supplied due to two factors which were linked - late date for 1970 Corvette production and the anticipated change to lower compression ratios for 1971.