{"product_id":"hks-g-cupring-90-8mm","title":"HKS G-Cupring 90.8mm","description":"\u003cp\u003e\u003cstrong\u003eSKU:\u003c\/strong\u003e \u003cspan itemprop=\"sku\"\u003e14999-AK037\u003c\/span\u003e\u003c\/p\u003e\n\n\u003ch4\u003e\u003cstrong\u003eHKS G-Cupring Head Gasket 90.8mm Bore 1.2mm Thick Nissan Skyline GT-R R32 R33 R34 RB26DETT\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp\u003eThe HKS G-Cupring metal head gasket fits RB26DETT engines in Nissan Skyline GT-R models from 1989-2002. This 90.8mm bore gasket with 1.2mm compressed thickness uses a bead-type G-Cup stopper and grommet design for reliable sealing in high-boost and high-compression setups up to 1500+ hp. It suits 86.5-87mm pistons common in stroked RB26 builds.\u003c\/p\u003e\n\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eG-Cup Stopper Design:\u003c\/strong\u003e Bead-type stopper reinforces cylinder sealing for high-boost applications.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrommet Construction:\u003c\/strong\u003e Folded stopper layer delivers consistent pressure and resists blow-out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e90.8mm Bore Size:\u003c\/strong\u003e Fits 86.5-87mm pistons in stroked RB26 engines.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.2mm Compressed Thickness:\u003c\/strong\u003e Supports higher compression with aftermarket pistons.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMulti-Layer Steel:\u003c\/strong\u003e Stainless steel construction handles heat and provides durability.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-Temp Coating:\u003c\/strong\u003e Enables easy installation and maintains long-term sealing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMade in Japan:\u003c\/strong\u003e Built by HKS to precise quality standards.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eProduct Notes\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003ePart number 14999-AK037 for 90.8mm bore and 1.2mm thickness with ±0.05mm tolerance.\u003c\/li\u003e\n\u003cli\u003eBore compatibility 86.5-87.0mm for 0.8-1.0mm overbore from stock 86.0mm.\u003c\/li\u003e\n\u003cli\u003eSingle gasket per engine weighs approximately 0.8-1.0 kg.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eProfessional engine builder installation required.\u003c\/li\u003e\n\u003cli\u003eBlock and head surfaces need RA 20-30 finish and must be flat.\u003c\/li\u003e\n\u003cli\u003ePair with ARP or HKS head studs and follow HKS torque sequence.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eThis Part Fits\u003c\/h4\u003e\n\u003ctable border=\"1\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eYear\u003c\/th\u003e\n\u003cth\u003eMake\u003c\/th\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eSubmodel\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e1989-1994\u003c\/td\u003e\n\u003ctd\u003eNissan\u003c\/td\u003e\n\u003ctd\u003eSkyline GT-R\u003c\/td\u003e\n\u003ctd\u003eR32 BNR32 RB26DETT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e1995-1998\u003c\/td\u003e\n\u003ctd\u003eNissan\u003c\/td\u003e\n\u003ctd\u003eSkyline GT-R\u003c\/td\u003e\n\u003ctd\u003eR33 BCNR33 RB26DETT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e1999-2002\u003c\/td\u003e\n\u003ctd\u003eNissan\u003c\/td\u003e\n\u003ctd\u003eSkyline GT-R\u003c\/td\u003e\n\u003ctd\u003eR34 BNR34 RB26DETT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUniversal\u003c\/td\u003e\n\u003ctd\u003eNissan\u003c\/td\u003e\n\u003ctd\u003eRB26DETT Swaps\u003c\/td\u003e\n\u003ctd\u003e86.5-87mm bore\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch4\u003eWhy Choose HKS?\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eJDM brand with decades of RB26 development and motorsport wins.\u003c\/li\u003e\n\u003cli\u003eG-Cupring design tested in 1000-2000+ hp RB26 drag and time attack engines.\u003c\/li\u003e\n\u003cli\u003eEngineered for reliable sealing in high-boost high-compression RB26 builds.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQ:\u003c\/strong\u003e What thickness options exist?\u003cbr\u003e\n      \u003cstrong\u003eA:\u003c\/strong\u003e 1.2mm standard plus 1.6mm and 2.0mm for lower compression.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQ:\u003c\/strong\u003e Does it need head or block machining?\u003cbr\u003e\n      \u003cstrong\u003eA:\u003c\/strong\u003e Direct replacement if deck surfaces are flat and clean.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQ:\u003c\/strong\u003e Is it reusable?\u003cbr\u003e\n      \u003cstrong\u003eA:\u003c\/strong\u003e Metal head gaskets are designed for one-time use.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eShipping \u0026amp; Handling\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMethod:\u003c\/strong\u003e Standard ground shipping.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAvailability:\u003c\/strong\u003e In stock - ships same or next business day\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging:\u003c\/strong\u003e Box dimensions approximately 18\" × 18\" × 2\".\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e Approximately 2-3 lbs package weight.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"HKS","offers":[{"title":"Default Title","offer_id":43821124419663,"sku":"HKS14999-AK037","price":50.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1062\/7920\/files\/hks-g-cupring-90_8mm-hks.jpg?v=1768435968","url":"https:\/\/www.blackopsautoworks.com\/products\/hks-g-cupring-90-8mm","provider":"Black Ops Auto Works","version":"1.0","type":"link"}