Piecing together the fuel system for the stroker in the wagon. Plan to make about 550hp.
Looking to do a 140gph electric pump. Would a return style regulator be better if this is going to be driven 90% street? I posted in this forum because i figured more " technical" guys would be in here. 3/8 to the carb, then 5/16 back to the tank be ok?

I don't see you over powering a dead head regulator with this pump.
Unless you are worried about under hood and fuel temp , I'd go this way.
If you have your heart set on a return system , I'd go with a bigger return for sure.

i don't think u need a return system. i run a mallory 140 pump, mainly street driven. i hit the strip maybe 3-4 times a year. 440 sb, 11-1 comp, 9.61@ 137.91. i have no fuel starvation or vapor lock issues. #10 from sump to reg, #6 from reg to carb. stay safe, seeya.