Yamaha TZ250/350 A-G 1973-1980 cylinder head rebuild kit, comprises of 2 x inner O rings pt.no.93210-70207, base gasket 383-11351-00. The cylinder head outer O ring original pt.no. 93211-94212, no longer available from Yamaha but a replacement O ring is available at 8.95(UK).See item ID 553. All items are available separately so if you only need one or two items please email us for a price. Don't waste your efforts using old gaskets and O rings for your rebuild! We have a good stock of them but do not hold engine parts.