327 Chevy Build
Article by Mark Trotta
The 327 Chevy engine featured in this article is from a 1966 Corvette. It is the L75 motor, which has a single four-barrel carburetor and was factory rated at 300 horsepower. The aluminium valve covers seen in the photo are not correct for this motor.
In 1962, the 283 Chevy small-block was bored to 4.00" and stroked to 3.25" making a displacement of 327 cubic-inches. A year later, Chevrolet began designating engines with letter/number codes. These most always started with the letter "L".
Stripping the block was the first order of business. Everything taken off the engine was cleaned, tagged, and put in boxes out of the way. Engine disassembly on a small-block Chevy is fairly straightforward.
The engine block was completely stripped before going to the machine shop. Machine work included cleaning the block, installing new cam bearings and freeze plugs, and boring the cylinders .030-inches.
Rebuilding the bottom end included pistons, rods, crankshaft, harmonic balancer, and oil pump.
Read: 327 Bottom End Build
In almost every small-block Chevy engine build, the camshaft is replaced along with the lifters. As with all phases of engine assembly, care must be taken while installing the camshaft.
Read: Install Camshaft in Small-Block Chevy Engine
Chevy 327 Cylinder Heads
The heads on this 1966 Corvette were original, casting #3782461. Date codes are J-12-5 and J-20-5 (October 12th and 20th, 1965). These were one of the best flowing factory heads GM had to offer for the small-block. Cylinder head assembly included checking, measuring, cleaning, re-assembly, and painting.
Lapping valves does not take the place of a valve job, but it does confirm whether or not one is needed.
Read: SBC Timing Chain, Gears, and Cover
To get paint to stick to a cast-iron engine block or cylinder head, the metal must be very clean and dry.
327 Chevy Build Before and After
Read: Spray Paint Engine Block And Parts
Following the cylinder head rebuild was the valve-train assembly, which included installing lifters, push rods, rocker arms, rocker nuts, and rocker balls.
Read: Valvetrain Assembly
L76 327 Small-Block
The L76 motor had a hydraulic cam and single four-barrel carb. With compression at 11.25:1 factory horsepower rating was 340 for 1963. In 1964, engine output rose to 365 horsepower.
L79 327 Small-Block
In 1965, Chevrolet released the L79, a 350-hp 327 engine with a single four barrel carb. This potent motor featured a Duntov solid-lifter cam, 11.0:1 forged pistons, forged steel crank and rods, and 2.02 intake valves.