How Much HP Can A 427 Small Block Engine Make & Did Chevy Ever Make One?

If you look through the long storied history of Chevy big blocks and small blocks, a couple of displacements will undoubtedly stand out. There's the venerable 350 small block crate engine used in dozens of GM products over the decades; the 327 famously used in second- and third-generation Corvettes; and the 454 big block that saw the limelight in Chevelles. 

Another Chevy-associated displacement occasionally shows up if you're around GM engines enough: the 427 small block. You might be thinking, "Isn't anything over 400 cubic inches considered a big block?" Well, if we are talking about motors that Chevy manufactures, then yes. The largest displacement small block that Chevy offers is 383 cubic inches. Chevy does make a 427 cubic-inch V8, but it's classified as a big block, and therefore has some architectural differences compared to the small block.

Other engine builders like Blueprint Engines offer engines greater than 400 cubic inches, like a 427, that are still referred to as small blocks. Instead of using a Chevy big block cooling jacket, port setup, and general big block architecture, it uses the design typically reserved for small blocks. The benefit is that you can use Chevy small block parts with them. Power-wise, a naturally aspirated Blueprint 427 "small block" crate engine throws out 540 horsepower right from the shop. That number can, of course, go a lot higher if you decide that a supercharger is right for you. 

Blueprint Engines offers this "small block compatible" 427 engine for $21,999. That gets you a big displacement engine (and included transmission) that punches above its weight class and is compatible with Chevy small block hardware. Smeding Performance also offers a 427 small block that, according to the builder, can put out 560 horsepower. Without accessories like the alternator, water pump, and flywheel, it will set you back $11,150. 

In comparison, Chevy's 427 cubic-inch big block engine makes 480 horsepower from the factory. Of course, 480 horses from what is essentially a turnkey motor is nothing to sneeze at. Yet up to 560 horsepower (again, without a supercharger) from an engine that carries the classic small block flexibility is in another class entirely. While Chevy may not be the one making the 427 small block, they do exist. In fact, thy have quite the powerful overall footprint.