SpeedFactory L19 Head Stud Kit for Honda B & K Series

SpeedFactory L19 Extreme Duty Head Stud Kit for Honda B and K Series

When you push serious boost into a B or K series, the factory head bolts stretch and the head starts to lift off the block, and that is how you blow a head gasket or worse. Head studs fix that by clamping the head down far harder and more evenly than bolts can. This SpeedFactory kit goes a big step past the usual upgrade: instead of the 8740 chromoly most head studs are made from, these are built for SpeedFactory by ARP out of L19, a premium quench-and-temper steel that holds a 260,000 psi tensile rating. That is roughly 25% more clamping strength than the off-the-shelf 8740 kits that top out around 190,000 to 210,000 psi. This is the head stud kit for the hardcore, high-boost drag motor that is lifting the head on everything else.

These are a direct drop-in for your OEM head bolts with no machining to the head or block, and they carry a hex broach on top so you can install them with the cylinder head already on the car if you need to. The kit comes complete with the L19 studs, nuts, washers, ARP assembly lubricant, and torque instructions. You will want a 9/16 inch 12-point socket for the nuts. The fitment covers the B and K series family, the B16A, B18C, B20/VTEC and LS/VTEC builds, and the K20 and K24.

Read this first: L19 is a race material, not a street fastener

This is the most important thing to understand before you buy, and it is the part nobody tells you. L19 gets its incredible strength at a real cost: it is highly susceptible to hydrogen embrittlement and stress corrosion. In plain terms, it rusts and weakens if it is exposed to moisture, and a corroded L19 stud can fail over time. ARP is blunt about this, the studs must be kept well-oiled at all times and not exposed to moisture, and ARP even recommends wearing gloves when handling them because skin oils and contamination matter. They ship individually wrapped in wax paper for exactly this reason.

What that means for you: this is a race-engine fastener for a car that gets run, maintained, and torn down, not a set-and-forget street part. If you are building a dedicated high-boost drag motor and you understand stud care, this is the strongest clamping you can buy for these engines. If you are building a street or street/strip car that will sit through humid summers and salty winters, L19 is the wrong tool, and you want ARP2000 studs instead, which are far more corrosion-tolerant and still plenty strong for the vast majority of builds.

Do you actually need L19, or do you want ARP2000?

Be honest about your power level here, because this matters more than brand loyalty. ARP designed L19 for applications where inertia loads exceed what ARP2000 can clamp, that is serious drag territory, generally builds boosting past 30 psi. Below that, ARP2000 head studs (220,000 psi) hold the head down just fine on a B or K series and they do not demand the moisture-control discipline L19 does. So if your build is targeting big boost and you are chasing every bit of clamp load, L19 is the answer. If you are running moderate boost on the street or at the strip, save the money and the hassle and run ARP2000. We would rather put you in the right studs than sell you more than your build needs.

Specs

What is in the kit

Fitment

This kit fits the Honda and Acura B and K series engines, B16A, B18C1, B18C5, B20/VTEC, LS/VTEC, K20, and K24, in the cars below. It is engine-based, so what matters is which engine is in the car.

Because this is an engine-based part, the listed chassis are a guide. What determines fit is the engine, so if you have a B or K series swap, match the kit to the engine, not the original car.

What to know before you buy

Beyond the L19 care requirements above, treat this like the race hardware it is. Follow ARP's torque procedure exactly and use the supplied ARP assembly lube, not motor oil, because the torque specs are calibrated to that