Readers' Tech Q&A
I have a 1971 Torino fastback with a tired 302. I would like to purchase a junkyard 5.0L from a newer model vehicle. I know the oil pan sumps are different. Instead of buying a kit, can I use my pan, pickup, timing cover, harmonic balancer, and flywheel from my original engine? Also, what years and vehicles should I be looking for to get a motor from? I am going to keep the engine carbureted.
There’s no replacement for displacement. Always! I’m assuming you want to replace your worn-out, two-barrel 302 with a later, more performanceoriented 5.0L engine and run a four-barrel carb— this is, after all, HOT ROD.
What’s “best” for performance while minimizing the need for additional, separate bolt-ons? Within these parameters, if you can find one, the most suitable late-model candidate would be a 5.0L H.O. from a 1985 Mustang. This motor was the first 5.0L with a hydraulic-roller cam, but still retained a carburetor—namely an emissions-legal descendant of a Holley four-barrel carb (but its intake manifold accepts any performance-oriented Holley 4150/4160-series four-barrel). It also has a non-computer, large-cap Duraspark II breakerless distributor, which already has a distributor gear that’s compatible with the roller cam (grab the control module on the driver-side inner fender plus the module-to-distributor wiring harness). Because this package was carbureted, it retained a mechanical fuel pump and the bolt-on camshaft fuel-pump eccentric.
After 1985, Mustang 5.0L H.O.’s came with a hydraulic-roller cam, but stepped up to computerized, sequential electronic port fuel injection (SFI). As you’re staying with a carburetor, for you they’d be a second choice, but because they were produced from 1986 through 1995 in a Mustang, availability is obviously much greater.
The SFI versions reached their peak with higherperformance GT-40 heads on 1994–1995 Mustang 5.0L-H.O. Cobra engines as well as the 1996–1997 Ford 5.0L-H.O. in the Explorer. The 1998 Ford Explorer received GT-40 heads but with a modified spark-plug angle, so they won’t always clear older models’ stock exhaust manifolds or exhaust headers.
Ford performance specialists, such as Advanced Engineering West’s Mark Sanchez, also caution you should stay away from the first 1986 SFI Mustang 5.0L engines: “1986 is not desirable—it’s junk.
Jump straight to a 1987 or later.”
Other options, less desirable from a performance point of view, include any non-H.O. Ford 5.0L with a hydraulic-roller cam. Roller cams were factoryinstalled in all 5.0L-equipped cars starting in 1986. Roller cams didn’t hit the truck line until 1992 (although all 1988-and-later trucks should have roller-cam-compatible cylinder blocks with provisions for installing the factory-type roller cam lifter retainer and dogbones).
Fuel-injected engines use a computer-controlled distributor, so you’ll have to transfer over the existing points-type distributor and coil. But who wants points? Now’s the good time to convert the points unit to breakerless. PerTronix is one conversion kit maker. Or you can buy a new MSD or PerTronix breakerless distributor and coil. If retaining your original points distributor, you must install a hydraulic-roller-cam-compatible distributor gear. This also applies to any new distributor that doesn’t come with such a gear preinstalled.
You can bolt a carbureted intake onto any fuelinjected engine. Factory 302 four-barrel intakes are rare, so you’ll need to get an aftermarket Edelbrock or Weiand intake if getting rid of the SFI.
Remember that even the “newest” of these latemodel engines is more than 20 years old. Unless you get incredibly lucky and find a wrecked car that just happens to have a newly rebuilt engine, your takeout will likely require a major refresh.
So much for retrofit options, but what other parts must be transferred or modified from your old engine to the new engine so it fits and
[ A 1983–1985 Mustang 5.0L-H.O. had a Holley four-barrel and a noncomputer Ford Duraspark distributor. Hydraulic flat-tappet cams were used in 1983 and 1984, but the rare 1985s added a hydraulic-roller cam, still with the Holley carb (block cast E5AE-HA or E6SE-DC). 1986–1995 5.0L-H.O.’s had SFI. Expect to pay $450–$800 at the wrecking yard for any of these motors.