Carburetor
The bolt-on
Our 383ci stroker test bed was fitted with a 650-cfm Speed Demon carb (70/78 jets); we stepped it up to a 750-cfm Mighty Demon mixer (75/83 jets). $550
The mule
'69 Nova with a 383ci small-block stroker running 10.5:1 compression, ported Dart Iron Eagle heads, and a Tremec TKO 600 five-speed trans, with an Edelbrock RPM Air Gap intake manifold and a 650-cfm Speed Demon carb. Power measured at the rear wheels.
Our take
The bigger mixer freed up some upper-rpm power without sacrificing torque, which is right in line with this ride's street/strip mission.
Before
Max torque: 363 lb-ft @ 3,700 rpmMax power: 314 hp @ 5,900 rpmAverage torque: 333 lb-ftAverage power: 278 hp
After
Max torque: 364 lb-ft @ 3,700 rpmMax power: 324 hp @ 5,800 rpmAverage torque: 340 lb-ftAverage power: 285 hp
Difference
+1 lb-ft+10 hp
Intake Manifold
The bolt-on
After outfitting our 383ci whipping boy with a bigger carb, we followed up by replacing the dual-plane Edelbrock RPM Air Gap intake with a single-plane Victor Jr. $196
The mule
The Nova with an Edelbrock RPM Air Gap intake manifold and a 750-cfm Mighty Demon carb.
Our take
As you might expect, the single-plane intake increased top-end horsepower at the expense of low-end grunt.
Before
Max torque: 364 lb-ft @ 3,700 rpmMax power: 324 hp @ 5,800 rpmAverage torque: 340 lb-ftAverage power: 285 hp
After
Max torque: 361 lb-ft @ 3,900 rpmMax power: 335 hp @ 5,800 rpmAverage torque: 361 lb-ftAverage power: 274 hp
Difference
-3 lb-ft+11 hp