Donald Farr
Former Editor, Mustang Monthly
May 13, 2006
Smeding's GT 347 Stroker is a 405hp version of the 347 Extreme. With 9.7:1 compression, it's a streetable engine that runs on pump gas.

Smeding Performance
We recently installed a Smeding Performance 347 Extreme into a '66 Mustang, so we have first-hand knowledge about the power and performance from a Smeding crate engine. Painted Ford Corporate Blue and dressed-out with Cobra valve covers, the engine replaced our worn-out 289 perfectly yet still maintains a vintage appearance. It's difficult to tell it's not an original 289.

Specializing in strokers, Smeding uses new Ford Racing blocks to build its Ford small-blocks. "It's getting harder and harder to find pristine used blocks for rebuilds," says Ben Smeding. "Because we use new blocks, there won't be rust in the water jackets, which is good for heat dissipation. Plus, the cylinder walls are nice and thick because the block hasn't been overbored."

The 380hp 347 Extreme is Smeding's bread-and-butter crate engine. The bottom end is put together with a nodular-iron crankshaft, forged I-beam rods with 3/8-inch ARP bolts, lightweight forged pistons, and a roller camshaft. Edelbrock aluminum heads with roller rocker arms top off the package, along with an Edelbrock RPM Air Gap intake manifold. A GT 347 Stroker version is also available with 405 hp.

Smeding's 347 GT is essentially the same engine as the 347 Extreme, only it uses GT-40 cast-iron heads and a flat-tappet cam. Horsepower falls to 325, but the price is also lower, approximately $800 less than the 347 Extreme. Ben says it's an excellent engine for daily drivers because the cam profile allows high vacuum for good fuel economy and drivability.

According to Ben, his 427 Cobra Special "revs like a small-block but feels like a big-block." That's because the big-inch 351, based on Ford Racing's Sportsman 5.8 block, is rated at 480 hp and nearly 500 lb-ft of torque. Internal components include a steel crankshaft, steel rods with 7/16-inch ARP cap bolts, forged pistons for a streetable 9.7:1 compression ratio, and a custom hydraulic-roller camshaft. Edelbrock Victor Jr. heads and aluminum intake top off the potent package, which was designed for Cobra kit cars but will work nicely in a vintage Mustang.

Description

Block

Heads

Cam

Intake

HP

Price

347 GTFord 5.0GT-40 cast-ironFlat-tappetPerformer325$4,295
347 ExtremeFord 5.0Edelbrock aluminumRollerRPM Air Gap380$5,495
GT 347 StrokerSportsman 5.0Edelbrock aluminumRollerRPM Air Gap405$5,495
427 CobraSportsman 5.8Edelbrock aluminumRollerVictor Jr.480$7,495