Torque Specs for March Performance Accessory Drive Systems: How Tight Is Tight Enough?

When you're building a show-quality engine bay with March Performance brackets and pulleys, getting the torque specs right is just as important as getting the fitment right. Our 6061-T6 aircraft-grade aluminum brackets are precision CNC machined to extremely tight tolerances — but that only works in your favor if the hardware is torqued correctly. Under-torque and components shift. Over-torque and you risk cracking or deforming the aluminum.

Here's a general guide to torque specs for March Performance accessory drive systems. Always refer to the specific instructions included with your kit, as specs can vary by application.

General Torque Guidelines

Bracket Mounting Bolts (to engine block)

• 3/8" bolts: 25–30 ft-lbs
• 7/16" bolts: 35–45 ft-lbs
• 1/2" bolts: 55–65 ft-lbs

Pulley Center Bolts

• Crank pulley bolt: Follow OEM spec for your engine (critical — do not under-torque)
• Water pump pulley: 15–20 ft-lbs
• Alternator pulley nut: 40–50 ft-lbs
• Power steering pulley: 25–35 ft-lbs

Accessory Mounting Bolts

• Alternator pivot bolt: 30–35 ft-lbs
• Power steering pump bolts: 20–25 ft-lbs
• A/C compressor bolts: 20–25 ft-lbs

Important Tips

Use a calibrated torque wrench. Never guess on aluminum components. A click-type torque wrench is the minimum — a digital torque wrench is even better for precision work.

Apply thread-locking compound where specified. Vibration from a running engine can back bolts out over time, especially on accessory brackets. Use medium-strength thread locker (blue) on most fasteners. Do not use red (permanent) thread locker on serviceable components.

Clean threads before assembly. Dirty or corroded threads give false torque readings. Chase threads with a tap or die if necessary before final assembly.

Torque in stages. For bracket mounting bolts going into the block, come up to final torque in two or three stages rather than going straight to max. This helps seat the bracket evenly.

Recheck after first heat cycle. Aluminum expands and contracts more than steel. After your first startup and cooldown, recheck all fastener torque. This is especially important on water pump and bracket bolts.

Why This Matters with March Performance Systems

March Performance brackets are machined from 6061-T6 aluminum and are 100% thicker than comparable cast brackets on the market. That extra material gives you a stiffer, more reliable platform — but it doesn't mean you can ignore torque specs. The precision fit of our systems means components align correctly only when hardware is at proper torque. A loose alternator bracket, for example, can cause belt misalignment that leads to squeal, premature belt wear, or thrown belts.

Browse our full lineup of Small Block Chevy serpentine systems, Ford serpentine systems, and LS serpentine systems at marchperformance.com. If you have questions about your specific application, call our tech support line at 1.888.729.9070.