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After spending a few months contemplating what induction modifications to make to our '88 LX project car, we've finally come up with a combination that we think will make for a strong runner, while meeting our driveability and budget requirements. Our criteria was simply that we wanted to significantly improve on the 13.89 ET we achieved with the bone stock 130,000 mile motor. Of course the notion of a power adder immediately comes to mind, but we're committed to naturally aspirated performance for the time being. So obviously the focus would entail improving on the inherent weakness in the five liter power plant - the cylinder heads. If you read our head shoot-out article, you saw how poorly the stock E7TE Ford castings flowed- an asthmatic 158 cfm on the intake side at .500. Selecting any one of the handful of aftermarket heads would result in as much as 40% better flow, and probably a 30-40 horsepower increase at the rear wheels. Toss in a intake manifold upgrade and we'd be looking at in the neighborhood of 50 horsepower at the rear wheels. The obvious question then is why not install a cam to round out the lung transplant? We gave this a great deal of thought and decided to stick with the stock cam for the time being. The main reason had to do with our criteria for keeping this project under a fairly tight budget. A cam upgrade would also mean stepping up to 24lb./hr injectors, corresponding calibrated mass air meter, and a larger throttle body. It made more sense to us to pick up a good set of heads, a decent intake, and leverage off the torque of the stock cam. Besides, the stock 5.0 HO cam is actually a decent grind, unlike the paltry flat-tappet cams Ford put in the early-era 289's and 302's.

Cylinder Heads
The dilemma then was how to select a head from the over-saturated 5.0 cylinder head market. With nearly a dozen head manufacturers, each with at least two castings in their catalog, you really can't go wrong with any of them. After some thought, however, we decided on the Holley Systemax heads because of their decent flow numbers out of the box. While they weren't the highest flowing head, we were attracted to them because of their good flow "under the curve", that is to say that their low and mid lift flow numbers looked impressive. We were also drawn to them because of their relative lack of review in other magazines. We've seen occasional installs of the entire Systemax kits, but so far we haven't come across anything on just the heads, or the heads matched with other brand induction parts. So we figured we'd be the ones to try it out!

Flow Data (from our Head Shootout article):

explorer intake

Intake Manifolds
The next decision was the intake. To be honest, there was really no hard thinking here. We simply came across an Explorer (i.e. Ford's top selling SUV) intake manifold for $200 -less than half the price of any aftermarket manifold. Because we like good deals, and since we dont have a big budget, we figured this intake would be a good step up from stock at a great price. The Explorer intake actually shares the same lower intake as the Cobra and GT-40, while the upper is dimensionally very similar to a Cobra. There are some reports that the Explorer intake flows better than the Cobra, while other says it flows the same. All we cared about is that it flows more volume than stock, and thus would be a good match for the better breathing Systemax heads.

Head and intake swaps are not difficult, but on a 5.0 they just take a lot of time due to all the accessories, electrical connections, and fuel injection components that have to be moved out of the way before you can access the heads. The best way to approach a head and intake swap is in three steps - disassembly, cleaning, and assembly. If you've never done the job before, figure six to eight hours to get the heads off. Another two hours to clean, and another four to six hours to reassemble. Give yourself several hours beyond that to tune the car afterwards and work out any bugs.

Aside from a good assortment of tools, you'll need to have head gaskets, intake gaskets, throttle-body and EGR gaskets, exhaust header gaskets, RTV silicone sealer, new head bolts, gasket remover, antifreeze, oil and filter. Expect to make a couple trips to the hardware store for stuff like longer upper intake bolts (needed for the Explorer intake) and other miscellaneous hardware.

(Head and Intake Installation.)
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Holley Systemax Heads
PN: 300-551-1

Approx. cost per pair: $1100
Material: Aluminum
Combustion Chamber Size: 61cc
Hardware: Complete
Mount Type: Pedestal mount
Runner Volumes: 175.5cc int. 70.9cc exh.
Valve Sizes: 1.94" intake 1.60" exhaust
50 State Smog Legal
Notes: Exhaust ports raised .400"



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