This is a D4TZ-9034-L:


But I need the opposite, so I am assuming this would be a D4TZ-9034-R. Correct?

 

No, probably not.
What are you working with? Year, w/ or w/o evap emissions, unleaded or leaded fuel?

 

Going by application of the one you listed, I assume you need one with the vent tube on the opposite side. D4TZ-9034-R is for trucks with evap emissions.
Same application without evap emissions. D4TZ-9034-M replaced by D5TZ-9034-A

 

76 Highboy w/o evap emissions, leaded fuel. Truck has a rear tank with the #
D8TA-9002-FB on it. The fuel filler that was on it has homemade and quite funky looking. I have one of the left vented fillers (first pic) but need one with the vent on the right.

 

You beat me with the answer. Takes me forever to respond on my phone. Thanks for the info Mike