Our pal, Roger "Dr. Air" Helgesen...
Our pal, Roger "Dr. Air" Helgesen spent some time exploring the possibilities for improvement with Chevy's best production iron heads. The Dr. observes that while intake-port flow is the strong suit of the Vortec head, the exhaust is mediocre. Our test heads were a used set of No. 062 casting Vortecs, which sell for about $500 a pair brand-new from GM. They received a mild prep and retained the stock 1.94/1.50-inch valve combination.
To grind or not to grind, that is the question. Here at the luxurious Car Craft office suites, this subject often sparks furious debate. After all, porting jobs are only as good as the guy behind the grinder, and repeatability for the average reader is questionable. While one person may sculpt righteous flow from lowly iron, another may turn a trick head to trash. Ported heads are a wildcard, because there's no telling ahead of time what you'll get, or what it'll cost.
Conversely, hot performance engines and headwork go hand in hand. Whether they're the work of highly paid pros or backyard hot rodders, worked heads top plenty of serious street mills and virtually all race powerplants. For skilled, budget-minded do-it-yourselfers, porting can be the great equalizer and can result in power levels that otherwise wouldn't be affordable--and there's a definite little-guy appeal that we can relate to. How do we quantify the porting wildcard in an engine build-up? Probably the best way is to show you how it's done. Want to weigh in? Drop us a line at carcraft@sourceinterlink.com and let us know if you like articles like this, or if you prefer out-of-the-box performance. For now, check out the sidebars below to see the potential that can be unlocked from stock heads by using a set of long cast-iron Vortec heads as an example.