I just typed this about dvalves on another thread...
https://passionford.com/forum/genera...ump-valve.html
People will tell you the frs won't idle right with an atmospheric dvalve but mine came with a bailey fitted and it's fine. If you disconnect the battery after fitting the car "learns" as you drive and the stalling at junctions stops.
Also you'll need a standard setup to replace it. Perhaps do a deal with luke who wants a d/valve?