Gain 50 Plus Horsepower with Dart Ford Heads

We used a Comp Cams Xtreme Energy flat-tappet hydraulic cam for allthree tests on our gallant 306. Combined with the Comp Cams 1.6:1 rollerrockers, this pushes the valves open to 0.519- and 0.523-inch lift.

With this kind of gain, we were excited about testing the 195cc heads tosee what kind of power we would see with the larger intake. Weanticipated that the low and midrange power probably would not improve,since the 170cc Pro1 heads would have the velocity advantage over thelarger 195cc heads. The larger heads did perform better compared to thesmaller Dart heads in the midrange from 3,000 to 4,000 rpm, generatingmore torque than the smaller Dart heads. Had we spent more time ontuning the smaller heads, it's possible we could have made more torquein this range since the air/fuel ratio was a bit lean in the midrangearea with the 170cc heads.

Swapping heads was easy enough on the dyno using new Fel-Pro head andintake gaskets along with a set of ARP head bolts to keep everythingglued together.

Our little 306 really responded to bolting on the alloy Dart heads thatwere worth a solid 52 hp and a nice torque boost almost all the waythrough the power curve over the stock iron Ford heads.

Looking at the peak numbers, the 195cc heads cranked out a serious 365hpachievement at 6,000 rpm and continued to carry only a minor drop inpeak power all the way through 6,400 rpm, which told us that had webolted in a bigger cam or perhaps a set of 1.7:1 rockers, we might havemade even more power. But let's not downplay a solid 52hp increase overthe stock iron heads with these out-of-the-box Pro 1s. If we're allowedto play "what-if" games, it appears that the larger 195cc heads would dobetter yet with a larger camshaft and more valve lift to take advantageof their greater flow potential.

Evaluating either of the Dart Pro 1 heads against the iron baseline,it's obvious that Dart has scored again for the small-block Ford fanswith a great selection of heads. Anytime you can bolt on 50-plushorsepower with a pair of heads that cost less than $1,000, that's abull's-eye where we come from.