New Suzuki Twisted Development Ported RMZ 450 08-23 OEM Cylinder Head 11100-28H00. Valves are 5.5mm. Uses 5.5mm diameter valve guides. Twisted Development came up with an epoxy resin on the intake ports for better air flow through the head. You can see the epoxy in the pictures. This item is in the category "eBay Motors\Parts & Accessories\Motorcycle Parts\Engines & Engine Parts\Cylinder Heads & Valve Covers". The seller is "mxsocal" and is located in this country: US. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech Republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, Korea, South, Indonesia,…