OK, lets get this out of the way right now$4,800 isnt cheap for a small-block Chevy, and 540 hp isnt unheard of. But making 540 hp for 4,800 bucks on pump gas is a big deal! To be fair, that price doesnt include headers, a distributor, a water pump, or plug wires, but it does include an expensive carburetor, machine work costs, and most of the little items that add up to a lot of money at the end of the day. Its basically a bit more than you get when you buy any crate motor.
The foundation of this project is a 383 stroker short-blockthats a regular 0.030-over 350 block with a 3.75-inchstroke crankshaft. Actually, it was a short-block weve had around here for a few years, and its gone through several incarnations, starting as a 335hp tow-rig motor and evolving into a mild 435hp street/strip mill that propelled two of our project cars for several years and several thousand miles. Eventually the skirts collapsed on the cheap cast pistons (might have had something to do with all the dyno-flogging, dragstrip testing, and nitrous!) and it started burning oil faster than gas. So it was time for the stroker to enter yet another phase of its life after some freshening up.
Dont be fooled by magazine writers who try to tell you that torque is more important than horsepower just because they built an under-cammed engine with weak cylinder heads. A good engine combination produces lots of horsepower and torque, and a good way to compare any two engines is to calculate how much of each they make per cubic inch of displacement. Kicking out 542 hp and 517 lb-ft of torque, this 383s production works out to 1.41 hp/ci and 1.35 lb-ft/ci. And with the benefit of hindsight, we think we could have made even more power by swapping on a set of 1.6:1 roller rockers and a bigger 850- or 950-cfm carb, although the carb could introduce driveability issues and potentially run slower at the track if it softened up the bottom end. All things considered, we think this buildup represents a near perfect balance of price and performance.
Check out the details in the sidebars below.