Valve height micrometer

340 is the same valve height. So unless you have a narrower retainer it probably won't work. Unless I'm just doing something wrong! Which is possible Haha. I can get you some pics later this evening of the problem I'm having. I will get some pics of the tool in just a few minutes. I'm always willing to trade lol I could use a pushrod length tool and some checker springs, any miscellaneous parts you may have? PM me and we will talk about it.