Our Probe 331 is gently laid...
Our Probe 331 is gently laid into its new home with the aid of the new billet CNC-steel 5.0 EFI engine lift plate from Summit Racing. This is a trick piece in that it bolts to all current EFI lower manifolds including Holley (which we're using here), Trick Flow, Edelbrock, Ford, and more.
Horse Sense: While the 347 stroker has been wildly popular in the past, the 331-stroked variant of the Ford small-block is gaining in popularity. The 331's ability to make more rpm is one of its nicer features. The Probe 331 is created when a 3.250-inch crank stroke is matched up with 5.400-inch-long connecting rods and 4.030-inch forged Probe pistons. The 347 differs by using a 3.400-inch crank stroke with 5.315-inch-long rods and the same 4.030-inch forged Probe pistons.
A few issues back ("Just Right," Nov. '01, p. 37), our left-coast editor Tom Wilson followed along at the Probe Racing Components shop as its technicians screwed together a spanking-new 331 stroker for Editor Turner's purple coupe. The Mustang's aging 5.0 (a 306, actually) had been a test mule installed about six years and three transmissions ago. It was time for the engine to retire-which it did on the side of the road one day when a head gasket decided it didn't want to seal anymore.
The new Probe 331 arrived beautifully crated and ready for installation, save for a few valvetrain items and a new clutch. After uncrating the engine and setting it up on an engine stand, we stood there with notepads, keeping track of all the fittings, hoses, and so on that would be needed to install a fresh engine-a crate engine, if you will.
Thus, a story was born: Installing the 331 and noting the problems that creep up during a crate-engine installation. Of course, some things will differ (we changed intakes, and thus needed different lengths of vacuum line) from your crate-motor install, but it will nonetheless get you thinking ahead of time for all the little things that frustrate and prolong the process.
Since our Probe 331 arrived...
Since our Probe 331 arrived sans valvetrain, we placed a call to Crane for a set of Gold Race adjustable roller rockers in 1.6:1 ratio, pushrods, and roller link-bar lifters to complete our long-block. Know what pushrod length you need (ask your engine builder) and get them ahead of time.
The Crane link-bar lifters...
The Crane link-bar lifters are much stronger than OE pieces and do not require the lifter bars or spring steel retainer that the OEs use. This means you can make any block into a roller-cam block without having to resort to additional parts or machining. The only downside is they will not install with the heads on, thus we had to crack open our fresh engine to install these lifters. But as the lifters are also good for a few hundred more rpm versus the stockers, we deemed the extra effort worthwhile.
After installing the new Crane...
After installing the new Crane lifters, a fresh set of head gaskets go on. Reinstall the aluminum AFR heads using torque specs provided by Probe. Make sure your new heads include the threaded end fittings for the front of the cylinder heads to attach your accessories or you'll be making another trip to the Ford dealer.
Next, our Holley lower intake...
Next, our Holley lower intake makes it to the new long-block. After installing the gaskets and applying a bead of silicone around the water ports on the ends, torque down the intake using factory bolts.
The rest of the '89 coupe's...
The rest of the '89 coupe's exhaust, which is comprised of a Bassani X-pipe and Edelbrock mufflers (with 211/42-inch tailpipes), will remain with the new engine combination, but we opted to throw new headers on our 331. In this instance, we're using JBA unequal-length 151/48-inch Cat4Ward Shorty Headers (PN 1624-2 with the optional silver high-temp ceramic coating) for ease of installation and to fit up to our existing exhaust. Sure, long-tubes might be worth a few more horses, but we already have a T56 six-speed and don't want clearance issues. As JBA says one of its project cars makes more than 900 hp with these headers, they seemed to be a great choice.
After pulling the wounded...
After pulling the wounded soldier from the coupe, we stripped it of all the items we planned to reuse. One of the first things we did was transfer all the intake items to the new Holley intake. The coolant transfer tube is installed here. Make sure there's adequate thread sealer on all fittings going into the intake. Some intakes need additional plugs or fittings; make sure you have them before starting.