Modified Mustangs & Fords
460 Big-Block Build - Large And In Charge, Part 1
Low-buck, mild modifications for a streetable 460 Ford
One of the most effective means of improving horsepower is to increase displacement, and one only need look at the current popularity of 5.0L and 5.8L Windsor strokers to illustrate the performance world’s affection with being large and in charge. We know the Windsor strokers are plenty powerful, but we know too that they aren’t the only motivational game in town. In fact, there are likely less expensive alternatives when looking for a replacement with displacement.
Best of all, these cost-effective replacements come from what must be considered humble origins. Take a stroll through the Ford/Lincoln section of your local wrecking yard and, likelier than not, you’ll find a dozen or so big-block Fords just begging for a new home. For now, we’ll dismiss the early 390-428 FE motors and concentrate on the big-boy 460s. Offered also in a slightly smaller 370- and 429ci displacement, the 385-series engines are simultaneously plentiful, powerful, and (best of all) dirt cheap.
From an enthusiast’s standpoint, the great thing about the 385-series engines is that in addition to the many Ford and Lincoln fullsize vehicles, they also found homes in marine, motor home, and industrial applications. The little-known 370 was used primarily in medium-duty truck applications, but the 429s and later 460s eventually became Ford’s bread and butter big-blocks. Rated at 370 hp in 1970 (375 hp for the Super Cobra Jet), the 429 Cobra Jet and SCJ were the weapons of choice for dragstrips and NASCAR alike. Underrated by Ford, these Cobra Jet motors likely put out more than 400 hp thanks to wilder cam timing, a static compression ratio that exceeded 11.0:1, and a sizable Holley carburetor.
Now that we have whet your appetite, forget everything you’ve read about the 429 Cobra Jet and Super Cobra Jet engines, as the supply of those ultra-rare engines has long since dried up. Of course, that doesn’t mean you can’t build something even more powerful, and selecting the larger 460 is a significant step up the proverbial performance ladder.
Since the 429 was offered for only a few years, Ford eventually relied on the 460 all through the ’70s, ’80s, and early ’90s to do the heavy lifting. Though never offered in Cobra Jet or Super Cobra Jet guise, the abundance of 460s makes them dirt cheap and easy to come by. Available in wrecking yards, we found a complete engine (including accessories and everything under the air cleaner) available at a local Pick-a-Part for the paltry sum of $265, plus core. For the serious penny pincher, our Pick-a-Part had sale weekends where everything was 50-percent off, meaning a complete running engine was available for as little as $130, plus a core charge of $65. How can you go wrong with a complete running engine that costs less than $200?
When you go looking for an engine, especially if you plan on running it as is, make sure to do your homework and thoroughly check out each potentially viable candidate. Since the oil will likely be drained, don’t hesitate to pull a valve cover to check for telltale signs of abuse or neglect. Is there oil sludge present or does the head look clean? Does it look like it might have been rebuilt recently (like ours), or does it look like it spent every inch of those 200,000 miles lugging ore deep in some coal mile?
Pull the plugs, check for coolant leaks (stains) and generally give it a thorough inspection (including spinning it over) before making your decision to pull and purchase. We even dropped the oil pan for a quick look. That’s what sealed the deal on our engine, as the 460 obviously had recent work done. Before pulling the engine, we even filled it with oil and fired it up briefly using a battery we brought for just such a purpose.
Chances are your 460 will be equipped with standard cylinder heads, but there are variations of the standard 429/460 heads that are more desirable than others when it comes to modifications. Though they can be made to thump out pretty decent torque, the later ’88-up EFI 460s should be avoided in favor of the early carbureted variety. Within the carbureted contingent, the early (pre-’72) engine (both 429 and 460s) featured cylinder heads with smaller (74- to 77cc’s) combustion chambers versus 90 cc’s for the later heads. Not surprisingly, the pre-’72 engines offered additional performance even in stock form thanks to higher compression ratios (10.5:1 versus 8.5:1). Early 460s were rated at 365 hp (remember the 429 Super Cobra Jet was rated only 10 hp higher), while the power output of the ’72 460 plummeted to just 212 hp. Some of the power difference between the ’70 and ’72 engines can be attributed to the change from gross to net power ratings. Gross ratings were derived in optimized configuration on the engine dyno before accessories, while net ratings were given in as-delivered tune with accessories (still flywheel rated). Regardless, the early engines with high compression will make more power and everything that follows about the build up of the 460 applies to its little brother, the 429.
The base heads (like ours) that you’ll find on an early 429 or 460 will likely feature rail rockers and screw-in rocker studs, along with a 2.07-inch/1.64-inch valve package. This compares to the 2.42-inch/1.72-inch valves used in the Cobra and Super Cobra Jet heads, and slightly smaller 2.19/1.66 in the Police Interceptor heads. A common upgrade for these base heads is to install the Cobra Jet-size valves. When combined with a little porting, these base heads can perform impressively, with 650-700 hp possible on the right combination. It should be noted that the smaller combustion chambers on these early heads make them less sensitive to detonation. Some sources claim that static compression ratios as high as 11.0:1 can be run on pump gas, but this would likely depend on the cam and ignition timing. Run with cold water in a marine application, we can certainly see this as a possibility, but we’d recommend keeping the compression near 10.5:1 for pump gas. The downside to the rail rockers mentioned previously is that they aren’t suited to performance use with higher-lift cams, but since the early heads are equipped with screw-in studs, aluminum roller rockers (and attending guideplates) are an easy swap. Later heads featured positive-stop pedestals for non-adjustable rockers.
All of the base 429 and 460 engines will be topped by a cast-iron intake manifold. Our 4V engine featured an Autolite carburetor, but there were two-barrel versions as well. If you’re going to change the intake and install a mild hydraulic flat-tappet cam, as we did in Part 1 of this 460 buildup, then it matters not which engine you start with as both offered the same compression and cylinder heads. The difference in power rating between the 2V and 4V versions of the 429 was 40 hp. According to our data, the early 460 (ours came from a ’68 Lincoln) was offered only in 4V configuration. The engine had obviously been rebuilt some time in its life, as the bores measured 0.060-over, but there was no work done to the cylinder heads (the valvesprings looked new, but no evidence of any port work).
In Part 1 of Large and In Charge, we decided to subject the 460 to some mild performance mods, including a new carb and intake, roller rockers, mildly ported stock heads, and a small flat-tappet cam. We wanted to illustrate a low-buck approach to performance that would combine a low-cost hydraulic flat-tappet cam with porting to the stock head that can be done at home. Look over the captions to see how the 460 faired in Round 1 of its performance buildup. Check back with us next month as we crank up the heat on this 460 with a hotter cam, better heads, and a serious induction system. Is it possible to exceed 600 hp with the stock heads? We’ll let you know next month.