by Chirag Asaravala. Photography by the Author and Dart Engineering.

Even though it's been over forty years since the advent of the small-block Ford "Windsor"series engines, the popularity of building-up these motors appears to be greater then ever. Sure Ford has made considerable advancements in engine technology since the old 289, 302 and 351 motors, but the complexity of the 4.6 and 5.4 engines, coupled with performance parts selection and pricing, simply prevent these motors from gaining popularity with the average garage enthusiast. There is also the fact that a Windsor motor is easier to crank big power out of. Stroker kits are cheap, as are power adders. In fact, in the last several years we're seeing virtually every Ford enthusiast build a 302 or 351 based stroker when it comes times for a new motor.

Are you choking?
With so many guys building 347's and 427's, we're unfortunately also seeing a lot of horsepower left on the table due to poorly matched cylinder heads. There is no doubt in most guys' minds that the stock cylinder heads wont cut it for a stroked small-block. However many of the aftermarket heads are also not a good choice. Many of the well known heads on the market were designed around stock displacement figures and their sub-200cc intake runners are a stretch when it comes to maximizing the potential of a stroked Ford. Add in a blower and there is no doubt that bigger gains are probable with a better matched head.

If you've been following our own blown and stroked project (see High on Carbs) you may at this point be calling us hypocrites. If so, you'd be right. After all we put ported World Windsor Jr heads (170cc intake runners and 1.94 valve) on a 331 cid motor. Then we went and added 8lbs. of boost via a Vortech supercharger. Sure the motor still cranked out 516 horse to the wheels, but we know the heads were holding us back. In fact, making our decision to seek out new heads was made even easier by the fact the 54cc combustion chamber yields a boost-unfriendly 10.5:1 compression ratio. So when the opportunity came up to evaluate Dart's new Pro-1 CNC ported heads, we didn't need to be asked twice. In this article we'll look at the technology behind the heads. In an upcoming issue we'll bolt the heads on to our supercharged 331 and see what happens.

Impressive Resume
Dart of-course is a well known name in the bow-tie world. Their Chevy stuff has routinely been in NHRA and IHRA winners circles. Believe it or not, their Honda blocks and heads are also top players in the import classes. It is only recently that they've tapped into the Ford market. Fortunately for Ford fanatics they took their Ford offerings just as seriously as they do everything else. Dart first introduced all new Ford 302 and 351 blocks, in iron and aluminum with four bolt mains and a standard or tall deck heights. These stout blocks are completely re-designed and, other than dimensional similarities, they share none of the weaknesses of the stock blocks. In fact, many power addicts who have inadvertently cracked stock castings into a pair of four cylinder engines have turned to Dart iron blocks and gone on to make four digit power figures.

The most recent contribution by Dart to the Ford crowd is a selection of cylinder heads. Their Pro-1 aluminum heads are available in "as-cast" form or CNC ported. The as-cast heads are available as either 170 or 195cc intake runners (1.94 or 2.02" valve respectively.) The CNC program takes those volumes up to 210 or 225 cc's. Dart goes with 2.05" or 2.08" valves in the CNC heads respectively. All heads are setup with 1.60" exhaust valves. Table 1 below outlines the major features of the four available heads.