Engines & Engine Parts

Welcome to your headquarters for horsepower—the place to get everything you need to build real power and performance! We’ve got competition-proven crate engines, performance-matched...

Welcome to your headquarters for horsepower—the place to get everything you need to build real power and performance! We’ve got competition-proven crate engines, performance-matched top end kits, and complete rotating assemblies from the biggest names in the industry. You can add a set of high-flow cylinder heads to your powerplant, upgrade your valvetrain, improve your oiling system, or drop in a new set of pistons. We also have a complete selection of crankshafts, connecting rods, harmonic balancers, pulleys, and engine brackets. We even have everything you need to restore the horsepower that time has stolen from your...

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Results 1 - 25 of 1299

Harland Sharp Polylocks Rocker Arm Nuts PL716K

Harland Sharp Polylocks Rocker Arm Nuts PL716K

Rocker Arm Nuts, Polylocks, Roller Rocker Arms, 7/16 in.-20 Thread, Set of 4

Part Number: CSP-PL716K

5.0 out of 5 stars ( 1 )

Estimated Ship Date: Tomorrow

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Summit Racing™ SBC Cast Steel Roller Tip Rocker Arms SUM-141706PL

Rocker Arms, Roller Tip, Cast Steel, 3/8 in. Stud Mount, 1.5 Ratio, Polylocks, Chevy, Small Block, Set of 16

Part Number: SUM-141706PL

4.47 out of 5 stars ( 51 )

Estimated Ship Date: Tomorrow

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Harland Sharp Polylocks Rocker Arm Nuts PL038K

Polylocks, 3/8 in. Thread, .550 in. Diameter, Set of 4

Part Number: CSP-PL038K

4.75 out of 5 stars ( 4 )

Estimated Ship Date: Tomorrow

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Harland Sharp Polylocks Rocker Arm Nuts PL3800K

Rocker Arm Polylocks, Stud Girdle, Fits 3/8 in. Stud, Set of 4

Part Number: CSP-PL3800K

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Harland Sharp Polylocks Rocker Arm Nuts PL3761K

Rocker Arm Nuts, Polylock Style, Full Roller, 7/16-20 in. Thread, 0.600 in. O.D., 2.200 in. Height, Set of 4

Part Number: CSP-PL3761K

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Engine Works Polylocks 78-8

Rocker Arm Nuts, Stud Girdle Polylock, 12-Point, Non-Roller, 7/16 in.-20 Thread, 0.600 in. Slot Width, 2.60 in. Length, Set of 8

Part Number: EW1-78-8

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Engine Works Polylocks 76-8

Rocker Arm Nuts, Stud Girdle Polylock, 12-Point, Non-Roller, 7/16 in.-20 Thread, 0.600 in. Slot Width, 2.10 in. Length, Set of 8

Part Number: EW1-76-8

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Harland Sharp Polylocks Rocker Arm Nuts PL3760K

Rocker Arm Polylocks, Stud Girdle, Fits 7/16 in. Stud, Set of 4

Part Number: CSP-PL3760K

Not Yet Reviewed

Estimated Ship Date: Jul 28, 2026 if ordered today

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Estimated Ship Date: Jul 28, 2026 if ordered today

Harland Sharp Polylocks Rocker Arm Nuts PL3762K

Rocker Arm Polylocks, Stud Girdle, Fits 7/16 in. Stud, Set of 4

Part Number: CSP-PL3762K

Not Yet Reviewed

Estimated Ship Date: Jul 28, 2026 if ordered today

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Estimated Ship Date: Jul 28, 2026 if ordered today

Harland Sharp Polylocks Rocker Arm Nuts PL3752K

Rocker Arm Nuts, Polylock Style, Full Roller, Stud Girdle, 7/16-20 in. Thread, 0.550 in. O.D., 2.600 in. Height, Set of 4

Part Number: CSP-PL3752K

Not Yet Reviewed

Estimated Ship Date: Jul 21, 2026 if ordered today

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Estimated Ship Date: Jul 21, 2026 if ordered today

Harland Sharp Polylocks Rocker Arm Nuts PL3750K

Rocker Arm Nuts, Polylock Style, Full Roller, 7/16-20 in. Thread, 0.550 in. O.D., 2.00 in. Height, Set of 4

Part Number: CSP-PL3750K

Not Yet Reviewed

Estimated Ship Date: Jul 24, 2026 if ordered today

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Estimated Ship Date: Jul 24, 2026 if ordered today

Harland Sharp Polylocks Rocker Arm Nuts JN3913K

Rocker Arm Nuts, Jam Nut, 12-point, 7/16-20 in. Thread, Full Roller, Set of 4

Part Number: CSP-JN3913K

Not Yet Reviewed

Estimated Ship Date: Jul 29, 2026 if ordered today

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Estimated Ship Date: Jul 29, 2026 if ordered today

Harland Sharp Polylocks Rocker Arm Nuts PL3751K

Rocker Arm Nuts, Polylock Style, Full Roller, Stud Girdle, 7/16-20 in. Thread, 0.550 in. O.D., 2.200 in. Height, Set of 4

Part Number: CSP-PL3751K

Not Yet Reviewed

Estimated Ship Date: Jul 21, 2026 if ordered today

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Estimated Ship Date: Jul 21, 2026 if ordered today

Summit Racing™ BBC, Ford Modified V8, Cleveland, Big Block Cast Steel Roller Tip Rocker Arms SUM-141709PL

Rocker Arms, Roller Tip, Cast Steel, 7/16 in. Stud Mount, 1.72 Ratio, Polylocks, Chevy, Ford, Set of 16

Part Number: SUM-141709PL

3.88 out of 5 stars ( 24 )

Estimated Ship Date: Tomorrow

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Summit Racing™ Cast Steel Roller Tip Rocker Arms SUM-141701PL

Rocker Arms, Roller Tip, Self-Aligning, Cast Steel, 3/8 in. Stud Mount, 1.6 Ratio, Polylocks, Chevy, 305, 350, Set of 16

Part Number: SUM-141701PL

3.5 out of 5 stars ( 4 )

Estimated Ship Date: Tomorrow

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Crower Sure Lock Rocker Arm Nuts 86050S-16

Rocker Arm Polylock Nuts, Short Design, 7/16 in.-20 Thread, Set of 16

Part Number: CRO-86050S-16

4.85 out of 5 stars ( 26 )

Estimated Ship Date: Tomorrow

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Summit Racing™ Rocker Arm Stud Girdles SUM-141003

Rocker Arm Stud Girdle, Clamp-On, 7/16-20 in., Polylock, Aluminum, Black Anodized, Chevy, Big Block, Kit

Part Number: SUM-141003

1.0 out of 5 stars ( 1 )

Estimated Ship Date: Tomorrow

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Summit Racing™ Cast Steel Roller Tip Rocker Arms SUM-141702PL

Rocker Arms, Roller Tip, Self-Aligning, Cast Steel, 3/8 in. Stud Mount 1.6 Ratio, Polylocks, Ford, 289, 302, 351W, Set of 16

Part Number: SUM-141702PL

1.0 out of 5 stars ( 1 )

Estimated Ship Date: Tomorrow

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AFR Rocker Arm Stud Girdle Replacement Nuts 6214-16

Rocker Arm Nuts, Stud Girdle Replacement Nuts, Full Roller, Polylock, 7/16-20 in., 2.00 in. Overall Length, Set of 16

Part Number: AFR-6214-16

5.0 out of 5 stars ( 3 )

Estimated Ship Date: Tomorrow

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Summit Racing™ SBC Cast Steel Roller Tip Rocker Arms SUM-141707PL

Rocker Arms, Roller Tip, Cast Steel, 3/8 in. Stud Mount, 1.6 Ratio, Polylocks, Chevy, Small Block, Set of 16

Part Number: SUM-141707PL

4.71 out of 5 stars ( 7 )

Estimated Ship Date: Tomorrow

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Estimated Ship Date: Tomorrow

Summit Racing™ Cast Steel Roller Tip Rocker Arms SUM-141700PL

Rocker Arms, Roller Tip, Self-Aligning, Cast Steel, 3/8 in. Stud Mount, 1.5 Ratio, Polylocks, Chevy, Small Block, Set of 16

Part Number: SUM-141700PL

5.0 out of 5 stars ( 1 )

Estimated Ship Date: May 11, 2026 if ordered today

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Estimated Ship Date: May 11, 2026 if ordered today

Need It Sooner? We recommend these similar substitute parts:

COMP Cams Magnum Roller Tip Rocker Arms 1417-8

5 out of 5 stars ( 4 )

Estimated Ship Date: Tomorrow

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Summit Racing™ AMC, Ford Cast Steel Roller Tip Rocker Arms SUM-141708PL

Rocker Arms, Roller Tip, Cast Steel, 3/8 in. Stud Mount, 1.6 Ratio, Polylocks, AMC, Ford, Oldsmobile, Set of 16

Part Number: SUM-141708PL

3.94 out of 5 stars ( 17 )

Estimated Ship Date: Tomorrow

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Pioneer Rocker Arm Adjusting Nuts 850008

Rocker Arm Adjusting Nuts, Non Roller, Polylock, 3/8-24 in. Stud Thread Diameter, Set of 16

Part Number: PIO-850008

3.75 out of 5 stars ( 4 )

Estimated Ship Date: Tomorrow

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PRW Power 12-Point Poly Locks 1200123

Rocker Arm Nut, Power 12-Point, Polylock, 3/8 in. Stud, .550 in. O.D. Shank, Set of 16

Part Number: PQX-1200123

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Crower Sure Lock Rocker Arm Nuts 86051S-16

Rocker Arm Polylocks, Fits 3/8 in. Stud, Set of 16

Part Number: CRO-86051S-16

5.0 out of 5 stars ( 8 )

Estimated Ship Date: Tomorrow

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