GSB 120 1M is the blank i am going to use

again thanks everyone for their advise...
Now i find myself in another delima.. guides.. i had an idea of what i wanted but now i'm freaking confused. I originally wanted NSG but now after hearing some people talk at a rod building shop... I'm thinking about the HVSG.
I'm going to make a spining rod but i'm wondering if 40mm is big enough?