Best 400 Crank For 350 Block: Compare Stroke and Balance

#1 · Best Overall

1. Scat 4-400-3750-5700 Forged Crankshaft

• Weight: 77 lb

Best for: Forged 400-style crank builds.

Why it ranks #1: Its 3.750-inch stroke, 350 two-piece rear seal, 5.700-inch rod length and 2.100-inch rod journal are specified together.

Scat’s forged 4340 construction and 3.750-inch stroke give this Small Block Chevrolet crank a clear role among the 400-style options. Its description also specifies a 5.700-inch rod length, 2.100-inch rod journal, and two-piece rear seal, providing several concrete dimensions for assembly planning.

The 3.750-inch stroke marks this as a longer-stroke choice than the 3.480-inch cranks listed here, while forged 4340 construction distinguishes its material and build type. Scat specifies a 5.700-inch rod length and 2.100-inch rod journal, useful dimensions to coordinate with the connecting rods and rotating assembly. The description names a 350 two-piece rear seal, so buyers can consider that configuration alongside the stroke before proceeding with fit and installation planning.

Skip it if you need a 6.000-inch rod length with a 3.750-inch stroke; Scat 9-400-3750-6000 lists that combination.

This Scat fits builders seeking a forged 4340 Small Block Chevrolet crank with a 3.750-inch stroke and the listed 5.700-inch rod length. Check that rod dimension and the two-piece seal against the intended assembly.

Listed on Amazon as: Scat Crankshafts 4-400-3750-5700 Forged 4340 Crankshaft for Small Block Chevrolet

#2 · Long-Rod Option

2. Scat 9-400-3750-6000 Cast Crankshaft

• Weight: 121 lb

Best for: Cast 400 crank with 6-inch rods.

Why it ranks #2: The 3.750-inch stroke, 6.000-inch rod length and 2.100-inch rod journal are stated, along with a 400 two-piece rear seal.

A 3.750-inch stroke paired with a 6.000-inch rod length makes this Scat 9000 Series cast-steel crank a specific 400-style Small Block Chevrolet option. Its description also lists a 2.100-inch rod journal and two-piece rear seal, giving builders several fit details to compare before assembly.

The 3.750-inch stroke places this crank among the 400-style choices, while its 6.000-inch rod length distinguishes it from the Scat forged option with a 5.700-inch rod length. Scat also specifies a 2.100-inch rod journal, which buyers can coordinate with the connecting rods, and a two-piece rear seal for planning the rear-seal arrangement. Cast-steel 9000 Series construction completes the listed configuration and helps distinguish it from forged alternatives.

Skip it if you require forged 4340 construction with a 5.700-inch rod length; Scat 4-400-3750-5700 lists both.

Choose this Scat for a Small Block Chevrolet 400-style build requiring a 3.750-inch stroke, 6.000-inch rod length, and two-piece rear seal. Its cast-steel construction is the boundary for buyers specifically seeking forged 4340.

Listed on Amazon as: Scat Crankshafts 9-400-3750-6000 Cast Steel Crankshaft for Small Block Chevrolet

#3 · Early-Seal Option

3. Eagle 104003750 Cast Crankshaft

• Weight: 24.5 lb

Best for: External-balance 400 builds.

Why it ranks #3: It specifies a 3.750-inch stroke, early-style two-piece rear seal, external balance and use with a 5.7-inch rod.

A 3.750-inch stroke paired with external balance makes this Eagle crank a clearly specified choice for a Small Block Chevy 400-style build. The listing also calls out a two-piece rear seal and a 5.7-inch rod length, giving buyers concrete configuration details to compare with their intended assembly.

The 3.750-inch stroke identifies this crank as a longer-stroke option than the 3.480-inch alternatives in the roundup, while the Chevrolet 400 description clarifies its stated application. External balance and the 1870 bobweight are specified together, helping a builder account for the listed balance configuration when planning the rotating assembly. The two-piece rear seal is identified as early style, and the 5.7-inch rod length provides another dimension to match before installation.

Skip it if you require internal balance with a 3.480-inch stroke; Eagle 103523480 lists both specifications.

Choose this Eagle for a Small Block Chevy 400-style build calling for a 3.750-inch stroke, external balance, and early two-piece rear seal. Its 5.7-inch rod length and balance configuration are important assembly boundaries.

Listed on Amazon as: EAGLE SPCLTY Eagle Specialty Products 104003750 3.75" Cast Steel Crankshaft for Small Block Chevy

#4

4. Generic SBC 400 Crankshaft

Best for: Two-piece-seal 400 replacement.

Why it ranks #4: The title identifies a 3.75-inch-stroke SBC 400 crankshaft with a two-piece rear main, but provides little further fitment detail.

The listed 3.75-inch stroke and two-piece rear main identify this SBC 400 crankshaft’s core configuration for a builder comparing 400-style replacement options. The title also gives the part designation 91515400, while the supplied specifications identify ReplaParts as manufacturer; no further construction details are provided.

The 3.75-inch stroke is the key dimension stated in the title, so it lets buyers distinguish this option from the 3.480-inch stock-stroke cranks in the roundup. Its two-piece rear main designation is another practical fit detail to compare with the engine’s seal arrangement. The listing names the application as SBC 400 and identifies ReplaParts as manufacturer, but provides no material, balance, rod-length, or journal specifications to guide a more detailed assembly match.

Skip it if you require stated forged 4340 construction and rod dimensions; Scat 4-400-3750-5700 lists those details.

Consider this crank when the defining requirements are an SBC 400 application, 3.75-inch stroke, and two-piece rear main. Its sparse specifications limit how much assembly matching can be done from the supplied listing alone.

Listed on Amazon as: SBC 400 Crankshaft, Two-Piece Rear Main, 3.75" Stroke 91515400

#5

5. Scat 9-400-3500-6000 Cast Crankshaft

Best for: Cast-steel 3.500-inch stroke builds.

Why it ranks #5: Its 3.500-inch stroke, 6.000-inch rod length, 2.100-inch rod journal and 400 two-piece-seal description provide useful but less typical stroke detail.

This Scat 9000 Series crank combines cast steel with a 3.500-inch stroke, a useful distinction for Small Block Chevrolet builders comparing stroke targets. Its additional listed details—a 6.000-inch rod length and 2.100-inch rod journal—give buyers specific assembly dimensions to consider when matching the crank to their build.

The 3.500-inch stroke places this between the 3.480- and 3.750-inch choices in the roundup, helping a buyer focus on a particular crank geometry. Scat’s description specifies a 6.000-inch rod length and 2.100-inch rod journal, which are practical dimensions to coordinate with the connecting rods and rest of the rotating assembly. It also identifies a 400 two-piece rear seal and cast-steel 9000 Series construction; together, these details help narrow compatibility before installation.

Skip it if you require a 3.750-inch stroke; Scat 9-400-3750-6000 specifies that stroke and a 6.000-inch rod length.

This Scat suits Small Block Chevrolet builders selecting a 3.500-inch stroke and checking rod length and journal dimensions against their assembly. Its two-piece seal is specified, but its stroke is not the 3.750-inch 400-style option.

Listed on Amazon as: Scat Crankshafts 9-400-3500-6000 Cast Steel Crankshaft for Small Block Chevrolet

#6 · Longest-Stroke Option

6. PNBJN 4.0-Stroke Forged Crankshaft

• Weight: 1.76 oz

Best for: Forged 4.000-inch stroke option.

Why it ranks #6: The listing claims forged 4340 construction and a 4.0-inch stroke for a 350 small-block V8, but gives no rod or seal specifications.

A forged 4340 construction paired with a 4.0-inch stroke gives this PNBJN crankshaft its clearest distinction for a 350 Small Block V8 build considering a longer-stroke configuration. The listing also identifies compatibility with GM350, so buyers can evaluate the stated engine application alongside the stroke and material before choosing an assembly.

The 4.0-inch stroke sets this apart from the listed 3.480- and 3.750-inch alternatives, helping buyers narrow choices by their intended crank geometry. Forged 4340 is the specified material and construction, while the title names a 350 Small Block V8 and the description gives GM350 compatibility. The listing also says its design aims to simplify installation and reduce engine vibration; those are stated goals, not dimensional details, so assembly planning still needs to account for the engine build.

Skip it if you need a stated 3.750-inch stroke and two-piece rear seal; Scat 9-400-3750-6000 lists both.

Consider this PNBJN option when a 350 Small Block V8 build calls for the listed 4.0-inch stroke and forged 4340 construction. Its listing does not state balance or seal configuration, so those details remain important fit checks.

Listed on Amazon as: Crankshaft Compatible For 350 Small Block V8 350-400 Crankshafts Engine Forged 4340 4.0 Stroke

#7

7. Eagle 103523480 Cast Crankshaft

• Weight: 35 lb

Best for: Internally balanced 3.480 builds.

Why it ranks #7: This small-block Chevy crank has a 3.480-inch stroke, internal balance and two-piece seal, but does not provide the longer stroke sought.

This Eagle crank pairs a 3.480-inch stroke with internal balance, making those two specifications its defining fit points for Small Block Chevy builders. The listing also identifies an iron crankshaft and a two-piece seal, allowing buyers to compare its core configuration with their intended engine setup.

A 3.480-inch stroke makes this Eagle an option for builds targeting that dimension rather than the 3.750-inch stroke listed on several 400-style choices. Internal balance and the two-piece seal further define the setup, helping a builder compare crank requirements with the rest of the rotating assembly and rear-seal arrangement. Eagle identifies the material as iron and the fit type as vehicle specific, but the supplied information does not add rod-length or journal dimensions.

Skip it if you need a listed 3.750-inch stroke and 6.000-inch rod length; Scat 9-400-3750-6000 specifies both.

This Eagle is a fit to consider for a Small Block Chevy build requiring a 3.480-inch stroke, internal balance, and a two-piece seal. Buyers needing rod-length or journal specifications should account for those unlisted details.

Listed on Amazon as: EAGLE SPCLTY Eagle Specialty Products 103523480 3.48" Cast Steel Crankshaft for Small Block Chevy

#8

8. Scat Pro Stock 9000 Crankshaft

• Weight: 53 lb

Best for: Stock-stroke small-block builds.

Why it ranks #8: Its 3.480-inch stroke, internal balance and two-piece seal suit a standard-stroke small-block build better than a 400-style stroker search.

Its 3.480-inch stroke keeps this Scat Pro Stock 9000 crankshaft in a stock-stroke configuration, making it relevant when a Small Block Chevy build calls for that dimension rather than a 400-style stroke. Internal balance and a two-piece seal further define the setup, so buyers can assess those requirements before planning the rotating assembly.

The 3.480-inch stroke is the central fit consideration: it distinguishes this crank from the 3.750-inch and 4.000-inch options in this roundup and suits a build requiring the listed stock-stroke dimension. Internal balance and a two-piece seal are specified, giving the builder two concrete setup details to coordinate with the rest of the engine. Scat identifies the material as iron and the series as Pro Stock 9000; those details help distinguish this part, but do not replace checking the complete assembly requirements.

Skip it if you need a 3.750-inch stroke; Eagle 104003750 lists that stroke with a two-piece rear seal.

Choose this Scat when a Small Block Chevy build calls for a 3.480-inch stroke, internal balance, and a two-piece seal. It is not the match for a 400-style 3.750-inch stroke, so settle the target stroke first.

Listed on Amazon as: Scat Crankshafts Scat CrankshaftsCrankshaft, Pro Stock 9000 Series, 3.480 in Stroke, Internal Balance, Iron, 2 Piece Seal, Small Block Chevy, Each