RE: Screamin Demon .65 build thread
A stand alone RNV is all you need, then send the metered fuel from the RNV into a spray bar on the intake that has no needle.
It's interesting to note that the Nelson spray bar channels the fuel into a spigot that dumps direct over the intake window of the crank, it practically rubs the crank. This is done to get the best possible fuel draw from an engine with an over sized [13 mm] venturi.