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I received my NOS PVC valve (AC-469) today. The threads on the inlet side are 1/4” male NPT and the outlet is 11/16”-18 female inverted flare. Thus the reason for this post.

I pictured buying a few adaptors and installing CuNi tubing to make the connection. Well that seems to be much easier said than done, as “No1300” found out, and I am finding out. An 11/16”-18 inverted flare is for 7/16” tubing. Difficult but not impossible to find but I don’t have a flaring tool for that size and I’m having difficulties locating an adaptor for this size tubing. Additionally, on the intake manifold I have a 1/4” pipe tee that I want to adapt the tubing to. So I would need a 1/4” male pipe to 7/16” tubing inverted flare adaptor which seems impossible to find.

Thinking that using 3/8” tubing would be much easier to find the adaptor fittings needed, I started searching for the adaptors. That is also proving to be difficult. I can find a 1/4” male pipe to 3/8 tubing but finding a 11/16”-18 inverted flare to 3/8” tube fitting or even a adaptor to go from 7/16” to 3/8” has produced no results.

My next thought for a possible solution would be to find a power steering fitting (11/16”-18 inverted flare) to AN connector, cut off the AN side and tap it for 1/4” female NPT. Then I can buy 1/4” male pipe to 3/8” tube (5/8”-18 inverted flare) fittings.

And of course I could try to find an original setup.

I really would like to keep it hard piped, so if any of you ‘bolters care to brainstorm, I’d appreciate your input.