Which models are considered Big Twins?

Big Twins refer to larger displacement Harley-Davidsons, including Flathead, Knucklehead, Panhead, Shovelhead, Evo, and Twin Cam.

Do I need any special tools for installing custom Big Twin parts?

Basic hand tools usually suffice, but some installations (like welding) may require specialized equipment or professional assistance.

Can I return items if they don’t fit my Big Twin?

Absolutely. As long as the part is in original, unused condition, you can return it according to our standard return policy.

Harley-Davidson Big Twin Parts

Sort by

Lowbrow Customs WX Split Gas Tanks - Bolt-On for 1936 - 1984 Big Twin Harley-Davidsons - 2.25 gallon
84 reviews $399.99

Colony #9870-16 Inner Primary Mounting Kit 1986-1993 Harley-Davidson Softail 1991-1993 Dyna Glide
1 review $24.00

Colony #9810-4 Smooth Rear Axle Nut & Spacer Kit 1984-1999 Harley-Davidson Softail - Chrome Plated
$57.94

Colony #9728-36 Head Bolt Set 1940-Up Harley-Davidson Flathead 45 1930-1947 74/80 Iron Head - Parkerized
4 reviews $97.04

Colony #9662-1 Gas Strainer Assembly 1950-1965 Harley-Davidson Big Twins - CAD Plated
2 reviews $76.76

Colony #9726-20 Head Bolt Set 1940-1947 Harley-Davidson Knucklehead - Parkerized
3 reviews $64.09

Colony #9725-20 Head Bolt Set 1936-1939 Harley-Davidson Knucklehead - Parkerized
2 reviews $64.09

Colony #9202-12 Pushrod Covers 1984-Up Harley-Davidson Big Twin Evo 1986-1990 XL - Chrome Plated
1 review $66.63

Colony #9865-20 Upper Pushrod Cover Kit Harley-Davidson Big Twin Evo W/S&S Lifter Blocks - Chrome Plated
$50.08

Colony #9661-1 Gas Strainer Assembly 1939-1941 Harley-Davidson Twins - CAD Plated
$55.04

Colony #9859-20 Lower Motor Mount Kit 1988-2006 Harley-Davidson FLT/FLHT/FXR/FXRS - Chrome Plated
1 review $44.89

Colony #9522-22 Upper & Lower Motor Mount Kit 1937-1947 Harley-Davidson Big Twin Side Valve - CAD Plated
$43.82

Colony #9855-28 Upper & Lower Motor Mount Kit 1984-1999 Harley-Davidson Softail - Zinc Plated
2 reviews $42.00

Colony #9858-15 Custom Sprocket Bolt & Nut Kit 1985-Up Harley-Davidson FXWG/FXRS W/Spoke Rear Wheel - Chrome Plated
$39.11

Colony #9625-16 Lower Motor Mount Kit 1930-1936 Harley-Davidson VL All 45 's - Chrome Plated
$38.73

Colony #9856-15 Custom Sprocket Bolt & Washer Kit 1973-Up Harley-Davidson FL/FX/XL W/Spoke Rear Wheel - Chrome Plated
$37.66

Colony #9847-9 Banjo Style Oil Feed Line Fitting Kit 1936-1941 Harley-Davidson Knucklehead - Chrome Plated
$37.66

Colony #9707-18 Rear Fender Mounting Kit 1936-1957 Harley-Davidson Big Twin - Parkerized
2 reviews $42.00

Colony #9638-30 Rear Fender Rail Acorn Screw Kit 1958-1980 Harley-Davidson FL/FLH - Chrome Plated
$37.66

Colony #9407-1 11/16"-16 Thread Repair Tap Harley-Davidson All Split Cases
$37.66

Colony #9860-20 Lower Motor Mount Kit 1988-2006 Harley-Davidson FLT/FLHT/FXR/FXRS
$36.94

Colony #9532-13 Rear Crash Bar Mounting Kit 1936-1957 Harley-Davidson Big Twin - Parkerized
1 review $36.54

Colony #9857-10 Custom Sprocket Bolt & Washer Kit 1973-Up Harley-Davidson FL/FX 1973-1991 XL W/Cast Rear Wheel - Chrome Plated
$34.76

Colony #9200-33 Windshield Mounting Kit 1949-Up Harley-Davidson FL/FX/XL/K - Chrome Plated
2 reviews $33.67

Colony #9804-2 Handlebar Plunger 1931-1939 Harley-Davidson 45 Solo/Servicar 1931-1936 VL - Parkerized
$38.00

Colony #9698-18 Head Bolt Washer Kit 1940-1947 Harley-Davidson 45/74/80 Alloy Head - Parkerized
$33.31

Colony #9848-9 Banjo Style Oil Feed Line Fitting 1936-1941 Harley-Davidson Knucklehead - CAD Plated
$29.70

Colony #9421-21 Transmission Mounting Kit Late 1977-1986 Harley-Davidson Big Twin - Zinc Plated
$31.14

Colony #9201-33 Windshield Mounting Kit 1949-Up Harley-Davidson FL/FX/XL/K - CAD Plated
$31.14

Colony #9868-26 Inner Primary Mounting Kit 1970-1979 Harley-Davidson FL/FX
$38.00

Colony #9702-2 Intake Manifold Nuts 1936-1939 Harley-Davidson Knucklehead 1930-1948 Sidevalve (Except 45) - Parkerized
2 reviews $29.34

Colony #9786-11 Front Fender Lamp Wire Kit 1935-1947 Harley-Davidson All Models
1 review $30.00

Colony #9694-19 Oil Pump Mounting Kit 1936-1967 Harley-Davidson OHV Big Twin - Parkerized
2 reviews $27.50

Colony #9866-18 Transmission Mounting Kit 1986-Up Harley-Davidson FXST - Chrome Plated
$26.07

Colony #9869-24 Inner Primary Mounting Kit 1980-1985 Harley-Davidson FL/FX
$32.50

Colony #9827-12 Timing Cover Allen Screw Kit 1/4-20 1936-1970 Harley-Davidson After Market Cases - Chrome Plated
1 review $24.62

Colony #9639-22 Electrical Terminal Plate 1970-1977 Harley-Davidson FL/FX - CAD Plated
$35.00

Colony #9423-1 Threaded Cylinder Head to Manifold Nipple 1930-1948 Harley-Davidson 74 & 80 Sidevalves
1 review $22.80

Colony #9618-18 Jiffy Stand & Foot Clutch Lever Bracket Mounting Kit 1936-1978 Harley-Davidson Big Twin - CAD Plated
1 review $26.40

Colony #9612-13 Transmission Top Cover Screw Kit 1936-1955 Harley-Davidson Big Twin - Chrome Plated
$23.90

Colony #9412-19 Timing Cover Screw Kit 1937-1973 Harley-Davidson 45's - Chrome Plated
$30.87

Colony #9307-17 Primary Cover Screw Kit 1970-1980 Harley-Davidson Shovelhead - Chrome Plated
2 reviews $21.29

Colony #9739-2 Front Brake Cable Adjusting Screw 1941-1948 Harley-Davidson Big Twin 1941-1957 45 Servicar - Chrome Plated
$20.65

Colony #9410-27 Transmission Top & Side Cover Screw Kit 1937-1973 Harley-Davidson 45's - Chrome Plated
1 review $20.27

Colony #9630-2 Front Brake Cable Adjusting Screw 1941-1948 Harley-Davidson Big Twin 1941-1957 45 Servicar - Parkerized
$21.12

Colony #9711-5 Shifter Lever Stud & Bushing 1936-1954 Harley-Davidson - Parkerized
3 reviews $19.51

Colony #9699-12 Rocker Box Mounting Kit 1936-1947 Harley-Davidson Knucklehead - Parkerized
$19.51

Colony #9741-2 Front Brake Cable Adjuster 1950-1971 Harley-Davidson Big Twin 1971-1972 FX 1952-1972 XL - Chrome Plated
1 review $18.72

Colony #9514-2 Handlebar Plunger 1954-1974 Harley-Davidson FL 1971-1973 FX 1954-1973 XL 1954-1973 Servicar
$18.72

Colony #9620-13 Transmission Top Cover Screw Kit 1936-1955 Harley-Davidson Big Twin - Parkerized
1 review $17.88

Colony #9796-12 Timing Cover Screw Kit 1/4-20 After Market Harley-Davidson Cases - Parkerized
$21.30

Colony #9795-12 Timing Cover Screw Kit 1/4-20 After Market Harley-Davidson Cases - CAD Plated
$21.30

Colony #9789-17 Transmission Shifter Cover Allen Screw Hardware Kit 1991-Up Harley-Davidson Dyna - Chrome Plated
$17.14

Colony #9621-12 Timing Cover Screw Kit 1936-1969 Harley-Davidson Big Twins
3 reviews $21.30

Colony #9400-1 Steel Transmission Filler Plug 1958-1980 Harley-Davidson Big Twin - Chrome Plated
1 review $17.52

Colony #9836-5 Chrome Countersink Washer Set for 3/8" Flat Head Socket Harley-Davidson - Chrome Plated
1 review $16.73

Colony #9102-8 Cylinder Base Nut Set 1978-1984 Harley-Davidson Shovelhead OEM #16838-78 - Black Oxide
2 reviews $20.35

Colony #9762-16 Oil Pump Mounting Kit Allen 1992-Up Harley-Davidson Big Twin - Chrome Plated
1 review $16.38

Colony #9636-8 Handlebar Clamp & Gauge Mount Kit 1983-1994 Harley-Davidson FX/XL - Chrome Plated
$15.94

Colony #9737-1 Gear Box Adjusting Screw 1936-1964 Harley-Davidson Big Twin - Parkerized
1 review $15.52

Colony #9622-16 Lifter Base Screw Kit 1936-1953 Harley-Davidson Big Twin 1937-1973 45's - Parkerized
2 reviews $16.35

Colony #9515-2 Rear Axle Adjusting Screw 1993-1999 Harley-Davidson FXST OEM #47579-93 - Chrome Plated
1 review $18.16

Colony #9607-2 Oil Pump Relief Valve Plug 1968-1980 Harley-Davidson Big Twin - Chrome Plated
$15.14

Colony #9107-8 Rear Brake Caliper Anchor Arm Bolt Kit 1973-1983 Harley-Davidson FL/FX - CAD Plated
1 review $15.13

Colony #9017-5 Air Cleaner Mounting Screw & Lock Kit 1936-1955 Harley-Davidson Twins - CAD Plated
$16.94

Colony #9814-16 Lifter Base Screw Kit 1/4-20 Harley-Davidson Aftermarket Case - Chrome Plated
1 review $17.69

Colony #9603-2 Oil Screen Plug 1952-1965 Harley-Davidson Big Twin - Chrome Plated
$14.34

Colony #9863-5 Transmission Case Bottom Stud Kit 1984-Up Harley-Davidson Softail
1 review $13.55

Colony #9864-6 Grease Fitting Zerk Type 1936-1984 Harley-Davidson - CAD Plated
3 reviews $12.74

Colony #9633-50 Flatwashers Harley-Davidson FL/FX/XL OEM #6099 - Chrome Plated
6 reviews $14.52

Colony #9523-1 Oil Pump Check Valve Plug 1936-1980 Harley-Davidson Big Twin 1937-Up UL/45s - Chrome Plated
2 reviews $12.74

Colony #9644-2 Oil Screen Plug 1981-Up Harley-Davidson FL/FX - Chrome Plated
$11.96

Harley-Davidson Big Twin motorcycles are legendary for their raw power, distinctive style, and unmatched capacity for customization. From the Flathead and Knucklehead to the Panhead, Shovelhead, Evo, and Twin Cam, each Big Twin engine carries its...

If you’re looking to transform your ride—enhancing speed, comfort, or that unmistakable retro look—explore our Harley-Davidson Big Twin Parts collection. We have everything you need to customize your bike, whether you’re focusing on performance upgrades or eye-catching aesthetics.

Why Upgrade a Harley-Davidson Big Twin?

Boundless Customization: Big Twins allow for radical transformations—from stripped-down bobbers to vintage choppers—letting you express your unique vision.
Enhanced Performance: Boost horsepower, torque, and responsiveness with high-quality ignition kits, carburetors, and more.
Personalized Aesthetics: Whether it’s a retro-inspired racer or a comfortable tourer, your bike can reflect your style and riding needs.

Why Buy Big Twin Motorcycle Parts at Lowbrow Customs?

We curate top brands and rigorously test products for durability, fitment, and performance before shipping them out.
Variety of Choices: We offer a carefully curated selection of motorcycle parts for a wide range of Big Twin engines—from the Flathead and Knucklehead to the Panhead, Shovelhead, Evo, and Twin Cam—so you can find the perfect fit for your ride.
Expert Guidance: Need advice on installing a gas tank or swapping out your ignition? Our dedicated staff is here to help—from how-to videos to step-by-step articles.
Passion for Custom Builds: We’re not just sellers—we’re fellow riders who believe in the art of motorcycle customization. Count on our expertise to bring your dream bike to life.
Wide Selection & Fast Shipping: Our warehouse in northeast Ohio is stocked daily, ensuring you get the parts you need quickly. Plus, enjoy free economy shipping on U.S. orders over $99 and flexible return policy within 90-day & no return fee.

Our Featured Big Twin Motorcycle Parts Products

Ignition Kits & Carburetors: Gain more power and better throttle response by upgrading your ignition and carb system. A refined setup can increase speed, torque, and overall rideability.
Custom Gas Tanks: Our Big Twin gas tanks are crafted from high-grade steel, pressure-tested to prevent leaks, and available in multiple shapes and capacities. Achieve the perfect balance between form and function.
Handlebars & Controls: From vintage ape hangers to sporty drag bars, our collection of handlebars offers different heights, widths, and designs. Complete the setup with controls like grips, mirrors, and brake/clutch assemblies for a cohesive look.
Retro Accessories: Elevate your Big Twin’s retro appeal with add-ons like vintage-inspired seats, windshield options, saddle bags, or even a top-mounted box for touring. Personalizing these details completes the old-school charm.

Ready to Customize Your Harley-Davidson Big Twin?

Explore our Harley-Davidson Big Twin Parts collection today and transform your ride into the perfect blend of power, comfort, and style. If you have questions, reach out to our expert support team or dive into our installation guides for pro tips. Let’s make your dream bike a reality—shop now and gear up for the open road.

Read less

Harley-Davidson Big Twin Parts FAQ

STAY CONNECTED
WITH LOWBROW

NO SPAM, EVER. JUST GREAT STUFF. YOUR INFO IS NEVER SHARED.