The factory built crankshafts

Stock strokes offered by Chevrolet go like this. The 265 and 283 carry 3-inch strokes, both with the smaller diameter journals. The 327 has a stroke of 3.25 inches and is available in both small- and large-journal versions. The 302 crank goes goes back to the 3-inch stroke, but unlike the 265 and 283 crank, the 302 spins on large-diameter journals. The exception to this is the 1967 302 which had the small diameter journals. The 350 crank has a stroke of 3.484 inches - also with large diameter main and rod journals. The 3.750-inch stroke 400-inch crank is unlike any of the other cranks listed for the small block, it's cast, while many other cranks are forged. Rod journals are common with those of the late 327, 350 and 302, but 400's main journals are a one-off size for the small block at 2.65 inches. The bore of the 400-incher is 4.125 inches. One of the most popular of all combinations used to be the 327-crank-in-the-283-block trick. This can be done without machine work, but you'll need the early (small diameter) crank. There is a fly in the ointment though, and you should be aware of it before laying out cash for parts. Not all 283 blocks will accept an early 327 crank due to the counterweights on the crank contacting parts of the block. Two things you should not do is turn the counterweights off the crank or grind on the block until clearance is gained. The amount of material needed to be removed from the block is a bunch in at least one area and you are sure to hit water. Turning down the 327 counterweights will create a very bad imbalance situation so just keep trading or shopping until you come up with the right 283 block as described earlier . This 3.25-inch stroke by 3.875inch bore engine yields 307 CID when used with stock rods - which have to be the small-bolt, early rods. Don't confuse this home-grown mutation with the Chevy-built 307 which has a large-diameter cast crank and rods with the 3/8-inch bolts. The drawback to the Chevy-built 307 is its very-low-compression cast pistons. In the piston department (for the home-built 307) you have a choice of high-performance slugs, the 307 stock pistons or some of the TRW forged pistons which are the budget racer's dream come true. You can't use 283 pistons - they're the right bore but the wrong compression height. Because the late 327 block is also used for the 350 CID engine, a 350 crank can be laid in the 327 block. The stock parts combination gets out of hand in a hurry and so does the endless variety of stroke combinations which can be obtained by turning the project over to a crank grinder. On engines to be built on the basis of a 265, 283 or early 327 block, a large-diameter crank can have its rod journals reground on an offset to produce a non-welded stroker. The maximum stroke to be achieved by this method is 3-9/16 inch on a 350 crank. By welding up the journals and then turning,them down, most any stroke you can dream up.

One of the more popular combinations today is the 383, having a 400 crank ground to fit a 350 block. With a 3.75" stroke, a more perferrable rod to stroke ratio is achived and this combination produces excellent low and mid range torque. Another hot item is the 377, a 400 block with a 350 crank using special spacer beraings. Both of these combinations require special pistions to achive the required compression height. However, with the popularity of these engine combinations, the required components have become a "shelf" item at most speed shops and mail order performance outlets. We are working on an area of this site which will address the 383 and the 377 build up. As these pages are complete a link will be added here.

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