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Manifold Test - Ford Racing Boss 302 crate engine

Death of a Small-Block

By , Photography by , Grant Peterson

We've had this Ford 363-inch replacement bullet for Project Ron Burgundy for awhile now, but we've been waiting to optimize our current combination with suspension and traction before we plugged it in. Currently, the '87 Fox Mustang runs low 12s in the quarter-mile, or about 7.80 in the eighth-mile. With a weight of 3,200 pounds—including driver/owner Grant Petersen—and making 441 rwhp, the car should be running 11.70 instead of the 12.25s we managed to get out of the stock suspension. While we're working with Maximum Motorsports to figure out the wheelspin, we have been eye-hustling the engine gleaming in its crate. It wasn't long before it was out of the crate, then on the floor, then off to the dyno to see how much power it makes normally aspirated.

Since this Boss 302 crate engine engine didn't come with an intake manifold, we decided to test some popular Edelbrock setups to see which one made power where. In addition to entertaining us, it might enlighten you.

The Mill
The Ford Racing 363 is the latest version of the Boss 302 crate engine. With a bore of 4.125 and a stroke of 3.400-inch, it replaces the 347 engine and is advertised to make 50 hp and 50 lb-ft more. The foundation of the Boss 302 crate engine is the 8.2-inch deck Boss block, a mean piece of iron that can take up to 4.125 bores and a 3.500-inch stroke with no grinding or clearancing. There are other Boss blocks, with 9.2 and 9.5-inch decks. The short deck engine is for class racing, where the engine needs to be as low in the chassis as possible, but it uses a different intake manifold so you might not see them in street cars. The tall deck engine is designed for a swap into a vehicle that had a 351 Windsor, Cleveland, or FE.

Ford Racing is also killing the 331 and 347 crate engine programs. The 347 was designed around a production block that could only go 0.030, so it made little sense to Ford to continue using it when the Boss block had the meat to handle both more bore and more power. The 363 was born of this. It is a perfect swap for any car with a stock 289/302/5.0L engine. Everything will bolt up but the exhaust, since the Z head raises the exhaust port 0.625-inch, you will need to buy headers.

The M-6049-Z304DA or simply "Z" heads are available both ported and non-ported. The Ford Racing 363 Boss 302 crate engine comes with the unported version with 2.02/1.60-inch valves and a 63cc CNC combustion chamber. The intake manifold port is 204cc and the exhaust port is 85cc. The rocker arms are 1.65:1 with 7⁄16-inch screw-in studs.

The cam is a hydraulic roller with 232/240 degrees of duration at 0.050 lift and 0.580/0.602 lift. With the big single-plane manifold and a spacer it makes peak torque at 5,400 and peak horsepower at 6,600, so the cam is big enough to rev if you have enough air. The rods are forged I-beams and the crank is forged steel. The forged pistons are from Mahle. This combination has 10.1:1 compression so it will work on premium pump gas.

The engine comes from Ford Racing with everything but a carburetor and intake, flywheel, and pulleys. It comes with a standard rotation water pump for V-belt-type engines. Our test was run at Westech Performance in Mira Loma, California, using an 800-cfm and twin 500-cfm Edelbrock Thunder Series AVS carburetors with out-of-the-box jetting. Average timing was 33 degrees BTDC. The headers were Hookers with 13⁄4-inch primaries and 18-inch collectors.

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I'd lik to see the same test using the wilson spacer on the rpm airgap intake. I use a funnel web(equal to the super vic) on a 302/5.0 motor in my 90 coupe with tfs 3 cam, ported world sr heads that has very good street manners and drive anywhere with 4.30 gears.

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