What's the headstud of choice for the guys deep 9's or better? Are 1/2" studs needed?

Sounds like ARP L19's are your best selection.

Per Extremepsi:

ARP's L19 material (comparable to A1 Technologies H11 Tool Steel) is a premium steel that is processed to deliver superior strength and fatigue properties. L19 is a very high strength material compared with 8740 (standard ARP headstuds) and is capable of delivering a clamp load at 260,000 psi. It is primarily used in short track and drag racing applications where inertia loads exceed the clamping capability of ARP2000.


They are offered in both 6-bolt and 7-bolt versions for 1g DSMs. They can be purchased from multiple vendors on this site. Here is one such vendor:

http://www.extremepsi.com/store/product.php?productid=21007&cat=1848&page=1

I ask because I can get ARP 1/2" studs for just under $100. Is this what the big dogs are running or are they just using "L19's"?

Your welcome to do your own research. I have already offered my suggestion. As I am sure you are aware, a build such as this, is much more involved and costly. If you are worried about $100, you are in for a shock.

I've found 1 decent thread about 1/2 studs but it was a few years old. I'm looking to get more recent feedback

By the time you pay for machine work, and inserts to use regular 1/2" studs, you could just drop in some l19's.

The choice does depend on if you are using a 6, or 7-bolt block. The 7-bolts can be drilled and tapped for 1/2" studs, which are a big improvement over the stock 11mm. The 6-bolts are already a 12mm size, and have to use inserts to run the 1/2" stud which is only marginally larger than stock.

I have 12mm l19's in my car. While I'm nowhere near running deep 9's I have no coolant push issues with a billet 35r at 40psi on e85.

He's gonna be on stock rods donnie. If he can't get it done on a stock gasket and bolts, it's going to be putting rods out the side.

My vote goes to L19 studs. Won't regret it.

bastarddsm said:

He's gonna be on stock rods donnie. If he can't get it done on a stock gasket and bolts, it's going to be putting rods out the side.

Click to expand...

Actually this is for an aluminum rod engine I'm having built