4g63 Oem head gasket or Hks

How many of you running on oem head gasket and at what power level on evo . I know Andre was running Hks with block orings with good results, but I am wondering what is other people opinions. From what I see 99% people running oem head gasket up to 1000whp. Thanks!

Can't make a direct recommendation - there are folks who have a lot of experience that can, though.

What I would ask is what fasteners are you using for the head, as they have a direct affect on the clamping force holding the head down - OEM bolts/studs or aftermarket studs, stock diameter or oversized? The gasket is just part of the equation and the chaps will need to know that, and the expected boost level - power is a product of torque (boost) and rpm - some engine builders will bias their builds towards higher boost, some towards more rpm.

I am using arp custom age 625+ head studs (stock diameter) with oversize washers and oversize nuts because the one that comes with the studs are so tiny. Everything will be torqued to 95lbs-100lbs. I used oem head gasket before with block orings with good results. Car was making 750whp. Now I am building another engine that will push around 50psi boost on big turbo around 900-950 whp and I am wondering if I should stay with oem gasket or if I see any benefits going with hks gasket. I know that on that boost pressure everything is passed the safe zone but I am just wondering what people are using. Thanks!!

I only ever used the HKS stopper type 1.2 mm gasket and incorporated a stainless o-ring. It was effective at the 1100 whp range we got to but definitely not bullet proof. For reference I was running around 55-56 psi. While there's plenty of people making around the 1000 hp mark on a late model OEM gasket, if I was building a 4G63 these days to make that sort of power level I'd be inclined to go with the a copper gasket for water/oil sealing (sadly they do a terrible job of this but more on that soon), and aluminium/bronze sealing rings that locate into the top of the bores with a machined groove. This is the combination you'll see used in just about every pro mod or high boost turbo drag engine that's making serious power these days.

As stated, the copper gasket does a pretty terrible job of sealing the oil and water but there are copper gaskets from the likes of SCE that use a rubber embossed section around the oil and water galleries to improve sealing. Alternatively there is a loctite product that can be applied to the copper gasket that achieves the same aim.