Bore size is a huge factor...
Bore size is a huge factor in how well your motor will work. We like the idea of de-stroking factory combinations to give the engine a bigger bore relative to its stroke.
The 306/316-Cid Faker4.030-Inch Bore 327l/350 Block262/265l 3.00-Inch Crank1.815 CH (or 1.765 with the 262 crank)How can own one of Chevrolet's most famous engines for next to nothing? Go down to the junkyard and pick up a 350 or late 327 block, drop in the 3.00-inch crank from a late 265, and you've got a 302! Actually, if your engine has been bored 0.030 inch, you'd really get 306 cid, which is still very cool. Or, you could swap in the little-loved crank from the '75-76 262 with its 3.10-inch stroke and get 316 cid. This is also one swap that you could make work with the early 265 crank or any of the 283 cranks if you had an early 327 block with the small 2.30-inch mains. If you made this swap with the early 327 block and a stock 283 crank, you'd have a 302 that specs out precisely as the rare original, but it wouldn't be original so don't try to pass it off as one. Some early hot rodders used to punch 283s 0.125-inch over and call them 301s. We guess that'd work too.
The 311-Cid 0073.905-Inch Bore 283l/307 Block327 3.25-Inch Crank1.690 CHWe call this 311-incher 007 because it's actually a 307 in disguise. Although, with this motor there are two ways you can build one. You could simply bore out a stock 307 by 0.030 inch and drive away with 311 cubic inches, but that's not very much fun. Or, you could drop an early 327 crank into your '62-or-later 283 block, after boring it 0.030 inch, and get 311 cid. Or, you could turn the mains down on a late 327 crank so it would fit into the main saddles in your early 283 block, overbore it 0.030 inches, and you'd still get 311 cid.
The 316-Cid Oddball4.030-Inch Bore 327l/350 Block262 3.10-Inch Crank1.765 CHThis one is known as the Oddball, but if you built this 316-inch de-stroker, it may just turn out to be the best big-bore, short-stroke combination you could ever come up with using factory parts. Then again, if the books are wrong and the 262's stroke really was just 3.00 inches, instead of 3.100 like the books say, then you'll just be making your own 0.030-over 302, which is kinda' cool in its own right. We called that one the Faker just a little while ago, didn't we?
The 333-Cid Final Stroker3.905-Inch Bore 307 Block267/305/350 3.48-Inch Crank1.575 CHThe Final Stroker is an easy engine to build. For this combination to work you'll need to find any 3.48-stroke crank and drop it into a 307 block. This swap could stroke the oft-forgotten 307 and make a contender out of it. Plus, 333 is a nice number that rolls smoothly off your tongue, so it'd be a fun motor to talk about.
The Long and the Short of ItThis chart represents just 30 of the more than 120 hypothetical small-blocks you could build using factory parts. We're only showing the industry-standard 0.030-inch overbore here since, let's face it, any of blocks you may find in the junkyard could already have it or will probably need it. We've included the original bore sizes for reference on the bottom of the chart. There are about 90 more combinations we haven't listed that you could come up with by boring the blocks 0.010, 0.020, or 0.040 over. However, most experts agree that any small-block destined for street duty can handle no more than 0.040 over, and any race small-block shouldn't be overbored more than 0.030. The bold numbers indicate displacements that are merely stock engines bored 0.030 over. There is at least one stroker listed here, the 294, that should be avoided because it really won't work well and should not be built due to valve/block interference. We don't think the 3.48 or 3.75 strokes will clear the early blocks like the 265 and 283, either.