The Ultimate Guide to the Chevy 383 Stroker

Rod Length
There's much more to stuffing a longer-stroke crank into a small-block Chevy than just making sure the crank will clear the block. In the Origin of the Species sidebar, we outlined how the total height of the rotating assembly should compute to be roughly the same height as the engine's deck height. While a short rod like the stock 400's 5.565-inch piece will work, the angularity is rather harsh. A shorter rod pushes the piston into the thrust surface side of the cylinder wall, causing unnecessary friction and wear. Plus, short rods tend to expose more of the piston skirt out of the bottom of the bore at bottom dead center. This can cause durability and piston noise issues. Most 383 small-block stroker packages prefer the stock 5.70-inch-long 350-style rod, but there are also advantages to going with a 6.0-inch rod. A longer rod further reduces rod angularity during the combustion cycle, which reduces the side load on the piston and cylinder wall. But despite all the theories about long versus short rods, there is no solid evidence to suggest that there is significant power to be gained by using a longer rod.

All is not rosy with a long rod combination, however. Longer rods move the wristpin closer to the ring package. In tight situations, the wristpin overlaps the oil ring, requiring a support rail. This reduced compression height also creates less piston stability at higher engine speeds because of a shorter piston skirt length. The following chart outlines the three popular rod lengths and piston compression heights based on a 3.750-inch stroke. All these rod-length and compression-height combos will produce an overall assembled height of 9.008 inches, which allows roughly 0.017-inch piston-to-deck clearance with a stock deck height of 9.025 inches.

In this example, the 6.00-inch rod requires a compression height of 1.133 inches (SRP's 6.00-inch rod pistons use 1.125 inches). The height is close to the bare minimum of 1.000 that most piston manufacturers recommend, which is why the 5.700-inch rod is so popular. Longer rods are also heavier and can affect the overall bob weight of the rotating assembly. When mixing and matching parts, you'll want to avoid spending extra money to balance the system. This means that if you buy the crank individually, make sure the overall bob weight of the rods and pistons match the crank's designed bob weight. If you screw up here, it will cost big bucks to balance the crank.

We've listed several rods from several manufacturers that would work for a 383. This is only a partial list of the rods available from all the manufacturers. As an example, Scat alone offers five grades of connecting rods. Some are designed as stroker rods, while others are stock replacement rods that will need help to clear the camshaft. There's also the question of I- versus H-beam rods. All prices in the following chart are for a package of eight rods.

By Jeff "Smith,"

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