I start to diasemble the gas tank to install a better fuel tank line pickup and found the complete line from tank to block fuel pump is 3/8" diameter outer dia. and 5/16" inner

I got a new 1/2" outer diameter and 3/8" inner dia. refrigeration line to install.
Should I run a better fuel pump for this line ?,I am using a Carter #4889 ,120gph.
This pump is good up to what line size ???

The pump should be fine. Are you going to bend up a new line all the way up to the motor? I would buy one prebent from Ground Up, or OPGI, or Year One, if I were you.