If you can find a place that still stocks TRW the 427 number is 42007. I am pretty sure that Seal Power has them but you have to find a parts man that is willing to look for it. If you can find a place that stocks SBI they show them in their catalog and the main warehouse stocks them. You will have to go to a place that carries a stock of heavy engine parts, maybe a rebuilder. If you can't find any E-Mail me and I'll let you know where you can get them.