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In addition to the Extrude Honeported World Castings heads, we fit the 306 with an Edelbrock Victor Jr. intake. Since the 306 and 347 would be receiving a healthy Xtreme Energy cam, the Victor Jr. intake got the nod over the dual-plane Performer RPM. Every effort was made to maximize the power potential of the test motors. The Victor Jr. was installed out of the box with no porting or even gasket matching. Topping the Victor Jr. intake was a 650-cfm Speed Demon carburetor. As we saw, the 306 worked best with the smaller 650-cfm carb (the 750 was tried), while the added displacement and power output of the 347 required the larger 750-cfm Speed Demon. Naturally, each motor required minor jetting to maximize power and stabilize the air/fuel mixture during the dyno pulls.