Thread: Headgasket info thread

Everyone always says Mazworx headstuds and downs ARP?? Is there any reason why ARP is a worse option? ARP is quite a bit cheaper... Just curious since I have always used ARP's in my V8's and now the SR's

Never mind, I found the difference...

Mazworx SR20 headstud kit ARP2000 material 215,000 to 220,000 PSI - Price: about $200 shipped

ARP SR20 headstud kit 8740 Chrome moly 180,000 to 210,000 PSI - Price: about $141 shipped

8740 Chrome Moly: Until the development of today’s modern alloys, chrome moly was popularly considered a high strength material. Now viewed as only moderate strength, 8740 chrome moly is seen as a good tough steel, with adequate fatigue properties for most racing applications, but only if the threads are rolled after heat-treatment, as is the standard ARP production practice. Typically, chrome moly is classified as a quench and temper steel, that can be heat-treated to deliver tensile strengths between 180,000 and 210,000 psi.

ARP2000®: ARP2000 is an alloy steel that can be safely heat treated to a higher level, producing a greater strength material than 8740. While 8740 and ARP2000 share similar characteristics – ARP2000 is capable of achieving a clamp load at 220,000 psi. ARP2000 is used widely in short track and drag racing as an up-grade from 8740 chrome moly in both steel and aluminum rods. Stress corrosion and hydrogen embrittlement are typically not a problem, providing care is taken during installation.


I'm still sticking to ARP because of the price.. Really doubt there is any difference anyway

- check your head surface for flatness to the factory spec, just in case.

- Hopefully, you have a good torque wrench or get your torque wrench calibrated. This is the most important thing IMHO.

I installed a set of ARP head studs a month ago. Their new studs kit are made from ARP2000. You can see it on the head of studs. Mazwork head studs are made by ARP with Mazwork's spec.

And that was PN# 102-4701 ? ...and they bottom out in the block?

Yep, same part number.They should all be made out of ARP2000. The don't bottom out and still have the stops. Higher final torque value of 90 ft/lb.

so basically the updated the material, but didn't change the length to have them bottom out properly in the block? may be worth the extra $$$ to go mazworx.

Apparently, they feel there is enough thread area to not change. Can't really second guess them since they make fasteners for practically for every motors. If you going to build a wonder engine, then yes go with the Mazworx studs. The extra features, more block thread and thicker main shaft, might warrant the extra cost.

I forgot to add. The stock head bolts don't bottom out on the block. Something to think about.

if the factory head bolts bottomed out in the block, it would be near impossible to get a proper torque spec unless every single block and bolt is made with the upmost precision and is surgical clean.

The point can be argued both ways. You really just reinforced his point too. The bottoming out is not needed except for a very specific application. But there is no right or wrong answer to this. ARP studs have been used for a very long time and have a good reputation. But like all things, they are not perfect and some people have had a bad experience. Shit, the same could be said about Nissan in general.

Arguing about head studs is a moot point. At the end of the day you really need to ask, do the quality of parts I have purchased meet or exceed MY expectation?