i have the 6.0 with heads/cam supercharger @ 8 psi but the bottom end is all stock and i got used to it, I feel like i need more power.

i was talking with Allen and he is gonna make me a 408 forged bottom end and swap out the heads and stuff i have now onto it. i have a 3.25" pulley which should get me around 12 to 15 psi at least. will it be a very noticeable gain in power?