Main Studs

Main Studs: hold the bottom end together when you add power

Main studs replace the factory main cap bolts that clamp the main bearing caps to the block and locate the crankshaft. Where a stock bolt stretches as it threads into the block, a main stud threads in first, then a nut torques down against the cap - giving cleaner, more consistent clamping load and better main bore alignment. When you raise cylinder pressure with boost, nitrous or a rebuild, the caps want to walk under load. Upgraded main studs are the fix that keeps the bottom end tight.

What ThreePiece stocks in main studs

There are 17 products on this page from 2 brands: ARP, which accounts for 16 of the 17, and Industrial Injection with one kit. Prices currently run from $138 to $1,339 - the current range for what is in stock, not a fixed price. The low end covers straightforward stud kits; the high end is the Industrial Injection Dodge 12V 2nd Gen Gorilla Girdle with ARP XL main studs, a girdle-and-stud package rather than studs alone.

Product names cover a spread of makes: Nissan, Toyota, BMW, Audi, Suzuki, Dodge and Ford. Two products carry detailed fitment data, listing Toyota and Ford - the Toyota Supra and the Ford B5254 - across a year range of 1987 to 2005. Treat the make list as a guide and confirm your exact application before you order.

How to choose

The main decision here is studs alone versus a supported package. A straight kit like the ARP Ford 2.5L B5254 5-cylinder main stud kit is the right call when the block and caps are healthy and you only need better clamping load. On engines that push hard on the main webs, a girdle package like the Dodge 12V option ties the caps together and adds rigidity - that is why it sits at the top of the price range.

  • Match the kit to your specific engine, not just the make - the same brand lists different part numbers per application.
  • Studs are torqued to a spec and often want assembly lube; follow the maker's instructions for your kit.
  • If you are already splitting the block, do the bearings at the same time.

What else you need with it

Main stud work usually happens with the bottom end apart, so pair it with Bearings and, if you are going deeper, Pistons. Reassembly means fresh sealing surfaces - see Head Gaskets and complete Gasket Kits. For plumbing and oil-system parts on the same build, browse Fittings and Oil Filters. Everything here lives under the Engine Components section.

Fitment help and ordering

Not sure which kit fits your engine? Call fitment help at 813-535-5801 or reach us through Contact Us. All orders ship with free shipping, and Affirm and Katapult financing is available on financing for larger builds.

Main Studs: hold the bottom end together when you add power

Main studs replace the factory main cap bolts that clamp the main bearing caps to the block and locate the crankshaft. Where a stock bolt stretches as it threads into the block, a main stud threads in first, then a nut torques down against the cap - giving cleaner, more consistent clamping load and better main bore alignment. When you raise cylinder pressure with boost, nitrous or a rebuild, the caps want to walk under load. Upgraded main studs are the fix that keeps the bottom end tight.

What ThreePiece stocks in main studs

There are 17 products on this page from 2 brands: ARP, which accounts for 16 of the 17, and Industrial Injection with one kit. Prices currently run from $138 to $1,339 - the current range for what is in stock, not a fixed price. The low end covers straightforward stud kits; the high end is the Industrial Injection Dodge 12V 2nd Gen Gorilla Girdle with ARP XL main studs, a girdle-and-stud package rather than studs alone.

Product names cover a spread of makes: Nissan, Toyota, BMW, Audi, Suzuki, Dodge and Ford. Two products carry detailed fitment data, listing Toyota and Ford - the Toyota Supra and the Ford B5254 - across a year range of 1987 to 2005. Treat the make list as a guide and confirm your exact application before you order.

How to choose

The main decision here is studs alone versus a supported package. A straight kit like the ARP Ford 2.5L B5254 5-cylinder main stud kit is the right call when the block and caps are healthy and you only need better clamping load. On engines that push hard on the main webs, a girdle package like the Dodge 12V option ties the caps together and adds rigidity - that is why it sits at the top of the price range.

  • Match the kit to your specific engine, not just the make - the same brand lists different part numbers per application.
  • Studs are torqued to a spec and often want assembly lube; follow the maker's instructions for your kit.
  • If you are already splitting the block, do the bearings at the same time.

What else you need with it

Main stud work usually happens with the bottom end apart, so pair it with Bearings and, if you are going deeper, Pistons. Reassembly means fresh sealing surfaces - see Head Gaskets and complete Gasket Kits. For plumbing and oil-system parts on the same build, browse Fittings and Oil Filters. Everything here lives under the Engine Components section.

Fitment help and ordering

Not sure which kit fits your engine? Call fitment help at 813-535-5801 or reach us through Contact Us. All orders ship with free shipping, and Affirm and Katapult financing is available on financing for larger builds.