I'd like to replace the stock 5/16" sending unit in my '67 Impala with a 3/8" unit to supply the new big block. Has anyone else done this? Will a new sending unit from the parts store be of decent quality? Or should I swap in a used one? I only want to do this once.
I would recommend buying a 3/8ths sending unit with a return line as well as your fuel delivery will be more reliable if you pump a lot of fuel forward and return what you do not mneed. it keeps the fue pressurized toprevent vapor lock anf cools the pump.