2024 Catalog

Power Valves
• The power valve allows the carburetor to function much leaner for part-throttle fuel economy
but once the throttle is in a wide-open position, vacuum in the manifold drops to almost zero
and the power valve enriches the fuel mixture. When the engine is returned to basic partthrottle
operation and vacuum rises, the power valve closes up, leaning out the mixture. The
power valve is important because of its effect on every day, around-town drivability.
• The rule of thumb for power valve size selection is to
divide your highest part throttle manifold vacuum reading
by two and select the closest size smaller.
• Example: 8” Hg of manifold vacuum would use a 3.5” Hg power
valve. Holley power valves include gaskets (thread size: 1/2-28).
• Sold individually, includes gaskets
Standard Gas
High Flow Alcohol
2.5 075 125-25 N/A
3.5 075 125-35 075 125-135
4.5 075 125-45 075 125-145
5.0 075 125-50 N/A
A-C. Holley Carb Service Parts
A. .150 Alcohol Needle & Seat (2 Pk) 075 6-519-2
B. .110 Gas Needle & Seat (2 Pk) 075 6-500-2
C. .120 Viton Needle & Seat 075 6-518-2
A-C. Holley Carb Service Parts
A. Power Valve Plugs With Gasket 075 26-36
B. Pump Cam Assortment 075 20-12
C. Standard Brass Float (Center Pivot) 075 116-2
A-C. Holley Carb Service Parts
A. Bowl Gasket Blue Release (2 Pk) 075 108-83-2
B. Metering Block Gasket Blue Release (2 Pk) 075 108-89-2
C. Adjuster Needle & Seat Kit 075 34-7
Carb Rebuild Kits
• Economical way to build any Holley carb
• Includes fuel bowl gaskets, metering block gaskets,
base gasket, throttle body gasket, accelerator pump
diaphragms, needle and seats, power valves, bowl screw
gaskets and instructions
2300, 2BBL 075 37-1543
4150, Double Pumper 075 37-1544
4150, HP Double Pumper 075 37-1546
Throttle Return Spring for Holley
• Features 2 throttle return springs
on the primary throttle shaft
and 1 throttle return spring
for the secondary shaft
• All springs are relocated
for air cleaner clearance
• Bracket also features built-in
adjustable throttle stop
• Powder coated gloss black
FUEL/AIR FILTERS
A
A
B
Orange
Black
Standard Gas
B
Red
A
Pink
White
Brown
Throttle Return Spring Kits
• Universal kit, polished chrome finish
• Includes one set of heavy and one set of light springs, all mounting hardware, and
complete instructions
2300/4150 Series Holley®, Carb Mount Fits 2 BBL, 4 BBL
and Demon Carbs
Holley Jet Box Kit
• Contains (2) each of (36) different
jet sizes, ranging from #64 to #99
Green
Holley Jet Box Kit 100 68873
Carb Service Parts
Blue
B
High Flow Alcohol
5.5 075 125-55 075 125-155
6.5 075 125-65 075 125-165
7.5 075 125-75 N/A
C
C
C
085 64927
ENGINE FITTINGS FUEL/AIR
FILTERS
COOLING/
TANKS
DEGREASERS
& CLEANERS
ELECTRICAL/
GAUGES
DRIVELINE CHASSIS/
CONSTRUCTION
BODY
COMPONENTS
TOOLS SAFETY STEERING FRONT
SUSPENSION
Throttle Return Spring
100 68876-SP
REAR
SUSPENSION
HUBS &
WHEELS
WARNING:
Cancer and Reproductive Harm
www.P65Warnings.ca.gov
800-472-2464
97
BRAKES