That surprises me Col- very interesting.
My first Troll was an 89 Auto TB42 , I don't remember what gas system was fitted but it had a venturi on top of the carby fed by twin vapor hoses. Also ran an electric shuttle pump when the original mechanical pump went- maninly because Nissan wanted over $300 for a new one and a Faucet pump was only $40
Fitted HEI ignition , extended rotor, 4x prong plugs to deal with problems of engine "kicking" sporadically, ended up being resistance/dry joint in the main power feed wire near the fusible link beside the battery.
Also made up an overide to use the auto box like a manual with a H pattern shifter and TC lockup. Went really well, but had considerably more power on petrol no matter how it was tuned. I think the lack of power came form tha gas converter not being big enough capacity for the 4.2 , but really only ever used the petrol as a backup for when the gas tank went dry.