Best to talk to Mike Duncan about a CVH what he does not know about them is not worth knowing . He used to race them .
Mike has been out of the Morgan scene for some time now, and is recuperating from an illness if I remember correctly.
I may be wrong but I don't think he ever raced a CVH engined 4/4, a twin Cam engined one in the 60s , a BDA in the 70s , but most of the time he campaigned +4s on the track , and his 3 wheeler.