little facet cube pump will not supply enough fuel volume (flow) if the engine is destined to make any sort of horsepower... you need a pump that is capable of around 90 litre / hour ... 1.5 litres a minute ... the little cube pump falls well short.
I like to route fuel from the pump to a regulator (malpassi or filter king type with built in filters are nice) and then to a three way distribution block... one separate line to each carb from the fuel block, and the third outlet restricted down to 1mm and plumbed to the return fitting on the tank.
If the engine is destined to make good power (like 100hp at the wheels plus) there is a need for large 3/8 fuel lines ... 5/16 lines the flow gets marginal.
View attachment 12778
this was the start of plumbing up the last 1600 I built... 3/8 lines from three way distribution block to the carbs... have more pics somewhere of the finished job, just need to find them.
SteveC