anti slosh valve for first gen tank

[tuske427]

I'm looking for an anti slosh valve for my '67 firebird's gas tank I recently bought. As we know the older cars don't have any such thing so the fuel travels back up the filler neck upon fill up and makes a mess, not to mention during hard acceleration. Then there's the whole siphoning issue..

I've looked around and the closest I can find are anti slosh valves for diesel trucks. However, I haven't found one that is the right size.

I'm guessing I can get a filler neck from a junkyard tank from a newer model vehicle and clamp it on, but I was hoping that someone may have encountered this issue (Mr. Peabody??) and have a viable solution for it such as a close fitting match or a source for locating an aftermarket anti slosh valve.

any suggestions would be appreciated.

Thanks!