I might be wrong but I’ve not seen any of the Holley Retrobrights which are RHD compatible i.e. dip in the right direction.
I'm not aware of a directional "dip" on any lamp. The lens and/or reflector may be designed to disperse light directionally. Based on the photos I've seen, the Retrobright lens and reflector look pretty neutral to me, as opposed to many off the shelf 7" H4's, where the lens is designed to direct light to a side.
