Radix supercharger pully size? size does matter

i have the radix charger on my truck it caim with a big a** 3.70 pully i want to go to a 3.00 pully with a custom tune anny other suggestions? does anny internal work on bottom end need to be beefed up running 11 psi ??

how much psi you runnin now ?

about 7.5