{"product_id":"yella-terra-holden-304-5-0-efi-platinum-1-75-high-ratio-rockers-yt6767","title":"Yella Terra Holden 304 \/ 5.0L EFI V8 Platinum 1.75:1 High-Ratio Shaft-Mount Roller Rockers — YT 6767","description":"\u003cp\u003eYella Terra’s Platinum 1.75:1 high-ratio shaft rocker set is a race-oriented valvetrain upgrade for Holden EFI V8 engines using VN-style cylinder heads. The higher rocker ratio increases valve lift without relying entirely on more aggressive camshaft lobe lift.\u003c\/p\u003e\u003ch3\u003ePlatinum high-ratio construction\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eSet of 16 adjustable full-roller aluminium rocker arms.\u003c\/li\u003e\n\u003cli\u003eHigh 1.75:1 rocker ratio.\u003c\/li\u003e\n\u003cli\u003eWide-body aircraft-grade aluminium arms for high-RPM stiffness and resistance to deflection.\u003c\/li\u003e\n\u003cli\u003eSupplier technical table lists less than 900 lb maximum open spring pressure.\u003c\/li\u003e\n\u003cli\u003eOversize full-complement caged bearings with precision-ground trunnions.\u003c\/li\u003e\n\u003cli\u003eHardened chromoly roller tips.\u003c\/li\u003e\n\u003cli\u003eSupplied with 2-inch 7\/16-inch capscrews and matching pedestals.\u003c\/li\u003e\n\u003cli\u003eMaximum spring diameter: 1.550 in.\u003c\/li\u003e\n\u003cli\u003eShim set included.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eSupplier warnings and machining\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eYella Terra separately states a maximum recommended spring seat pressure of 380 lb for this application; seat pressure and open pressure are different measurements and both limits must be respected.\u003c\/li\u003e\n\u003cli\u003eRemove approximately 0.300 in from the rocker pads and drill\/tap the mounting points to 7\/16-inch UNC.\u003c\/li\u003e\n\u003cli\u003eRequires Yella Terra YT 5132 10 mm valve-cover spacer.\u003c\/li\u003e\n\u003cli\u003eYella Terra notes localised head clearancing may be required because of casting variation.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eApplication:\u003c\/strong\u003e Holden 304 \/ 5.0L EFI V8 combinations using VN-style heads. Because this is a high-ratio rocker, verify final valve lift, retainer-to-seal clearance, pushrod geometry and piston-to-valve clearance before operation.\u003c\/p\u003e\u003ch2\u003eProduct System\u003c\/h2\u003e\u003cul\u003e\u003cli\u003eEngine Parts\u003c\/li\u003e\u003c\/ul\u003e\u003ch2\u003eVehicle Fitment\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eHolden Commodore Vn Vr 5 0 Efi V8\u003c\/li\u003e\n\u003cli\u003eHolden Commodore Vs 5 0 Efi V8\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eConfirm chassis, engine, drivetrain and production-year compatibility before ordering.\u003c\/p\u003e\u003ch2\u003eSupplier Part Number\u003c\/h2\u003e\u003cp\u003eYT 6767\u003c\/p\u003e\u003ch2\u003eBuilt by Boost \u0026amp; Tune Support\u003c\/h2\u003e\u003cp\u003eBBT can assist with fitment review, installation, supporting modifications, configuration and calibration requirements where applicable.\u003c\/p\u003e","brand":"Yella Terra","offers":[{"title":"Default Title","offer_id":43816982609987,"sku":"YT 6767","price":1550.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0703\/0659\/4883\/files\/IMG_8601__84520.1659676783.jpg?v=1789167629","url":"https:\/\/builtbyboostandtune.com.au\/products\/yella-terra-holden-304-5-0-efi-platinum-1-75-high-ratio-rockers-yt6767","provider":"BUILT BY BOOST AND TUNE","version":"1.0","type":"link"}