B18 head, B18 bowl size, B20 valves. Has had B20 valves fitted and been relieved up to the valve seats. The sharp ridge in the bowls has been smoothed and polished. Bowls have been etched to the gasket line. All of these modifications directly improve the flow and performance horse power. Exhaust floors have not been touched. Performs brilliantly have used it myself. However was used with new valve springs from Brookhouse Volvo parts as the original valve springs are not in good condition; these are not included but the old springs and all collects and end caps are. The item "VOLVO B18 B20 Ported Cylinder Head & Enlarged Valves"…