 |
 On special 327 (and 283) blocks...  On special 327 (and 283) blocks made to fit the tight 1965-1967 Chevy II/Nova engine bays, the oil filter is recessed into the block about 1-1/2 inches. The clutch cross-shaft pivot (arrow) is located near the oil pan, 1-3/4 inches lower than standard. |
 The road-draft tube hole (arrow)...  The road-draft tube hole (arrow) was used on small-journal blocks. It was eliminated on large-journal applications. |
 The 1962-to early-1968 327s...  The 1962-to early-1968 327s had small-journal forged cranks; the flange was circular with two notches (arrow). |
 Introduced in 1968, large-journal...  Introduced in 1968, large-journal cranks added a small residual counterweight to the flange (arrows). The 350 crank flanges are more square-cut . |
The 327 was only in production for eight years, but in that time the engine would become a legend among small-block aficionados. What made the 327 so efficient was its large (for a small-block), 4-inch bore that readily accepted big-valve heads, combined with the relatively short 3.25-inch stroke. With standard small-block 5.7-inch rods, the combo yielded a 1.75:1 rod/stroke ratio, very close to the 1.80-1.85:1 ratio considered by many professional engine builders as optimum for an acceleration engine. Unlike with the later, longer-stroke small-blocks, installing longer aftermarket rods does not severely compromise piston design. In terms of cylinder feeding versus displacement, the 327-inch engine size seemed to dovetail perfectly with available cylinder-head port volumes and camshaft designs.
For all these reasons, many believe that, with the possible exception of the even rarer '67-'69 Z/28 302, the 327 has the most horsepower-per- cubic-inch potential of any small-block. That's important if you're racing in a class based on pounds per cubic inch; otherwise, raw inches are still king. And good luck finding a rebuildable core that'll clean up at 0.030-inch over. CC