By Richard Holdener
Fanatics have plenty of factory Ford performance small blocks to choose from, but a few notable candidates come right to mind. Of course Mustang owners must recognize the original 271-hp (HiPo) 289s, though hardcore guys might bring up the very limited run of 260-hp HP-260s that predated the 289.
A hot little number, the production HiPo 289 got very close to the then-magical number of 1 (gross) horsepower per cubic inch. Once some old chicken farmer sprinkled some magic fairy dust on the motor for GT350 and Cobra use, the power output jumped to 306 hp. On paper, the Shelby version of the HiPo 289 topped the power production charts for Ford small blocks until the Boss appeared.
Though the Boss 302 was rated at just 290 hp, the larger 351 checked in with 330 hp. In reality, both Boss motors easily made more power than the 289, Shelby or otherwise. After the Boss 351 was released in 1971, power outputs took a nose dive, and we wouldn’t see any real performance small blocks from Ford until the beginning of the second muscle car era in the mid 80s.
As fondly as we remember those early performance motors, the truth is, they take a backseat to what Ford eventually introduced in the mid-late ‘80s. After the big Blue Oval introduced the 5.0L on an unsuspecting market, Ford performance no longer took a back seat to the bowtie boys. 5.0L Ford owners could hold their heads high, and, no longer had to look back longingly at early Mustang performance.
Heck, a 5.0L LX would show taillights to any small-block Shelby, to say nothing of a HiPo 289 Mustang. Things progressed rapidly after the 5.0L, as Ford brought us Tenacious Terminators, supercharged Shelbys and even killer Coyotes, but the 5.0L is the motor that started it all.
Naturally, the aftermarket stepped up in a big way to enhance the vulernable little 302. Almost overnight, a flood of high-flow, aluminum cylinder heads, powerful camshafts and trick induction systems hit the market, allowing Mustang owners to step up from stock. The result was the ability to build a street/strip terror that could easily masquerade as a daily driver.
The popularity of the 5.0L spawned an aftermarket industry, which Ford owners enjoy to this day. Using the many performance components, building a stout small block is as easy as picking up the phone. The key to the available performance is what we refer to as the power producers, namely the cylinder heads, camshaft and induction system. The after market has made great strides in the last 30 years, so it should come as no surprise that we are able to surpass the power levels of yesteryear.
While one horsepower per cubic inch was once the holy grail of power output for the production powerplants, it is now commonplace, at least for any performance street motor. In fact, if you built a performance 302 that only made 302 peak horsepower, you should consider your project somewhat less than successful, unless your build up was more of a rebuild using primarily stock components. That we can now build a 302 that exceeds the power output of the early performance (and even race) motors should not be surprising. That it can be done so easily, and with excellent street manners, is all the more impressive. Not only can a 302 be built that exceeds 370 hp, but such a motor can be ordered with no more knowledge than your credit card number.
To illustrate just how easy it is to build Ford performance, we decided to let our fingers do the typing, and placed an order to BluePrint Engines for one of their many popular Ford offerings. Though BluePrint Engines (BPE) offered everything from performance parts to complete stroker combos, we elected to go the semi-DIY route. The strokers were certainly tantalizing, but in the end, we selected a 302-based combination. The bp306sp offered 306 inches thanks to a .040 over bore.
The short block started with a production 5.0L block machined to accept a cast crank, 5.155-inch rods and hypereutectic pistons. Before you dismiss the internals for their lack of the word forged, know that we have run endless stock short blocks with similar components. The stock stuff will support impressive power, enough to actually call the strength of the block into question, but we are getting ahead of ourselves here. The assembled short block also included a hydraulic roller cam (.543/.554, 218/226 112 lsa), lifters and a front cover. Completing the bp306sp was a complete oiling system that included a production Mustang oil pan.
The BPE short block had plenty to offer, but did require a few additional components before running on the dyno. We first installed a 50-oz damper, followed by a set of cylinder heads, intake and carburetor. Since we had a BPE short block, we decided to try a set of their heads as well. The 190-cc, as-cast heads (hp9008) featured a 2.02/1.60 valve package, 60-cc combustion chambers and flow rates that topped 250 cfm on our bench.
The heads were tipped by a dual-plane, Eliminator intake from Speedmaster. The polished dual plane was ideally suited for the sub-6,500 rpm combination. The final touches included a Holley 650 Ultra XP carb, MSD distributor and Hooker long-tube headers. Also present was a Meziere electric water pump, Lucas 5W-30 oil and Comp composite valve covers. Once dialed in, the BPE-headed 306 produced 371 hp at 6,100 rpm and 367 lb-ft of torque at 4,000 rpm. After assembly, the 306 combination worked perfectly and offered a broad torque curve, while the reasonable compression ratio hinted at things to come.
Sources: ARP; arp-bolts.com, BluePrint Engines; www.blueprintengines.com Comp Cams; www.compcams.com, Holley/Hooker/NOS; www.holley.com, MSD; http://www.msdperformance.com, Speedmaster; speedmaster79.com, Westech; http://www.westechperformance.com