Torino motor

Hi, just picked up a 68 torino gt fastback with a 302 with stock tranny and rear end, im planning to geet a new motor, my idea is to get a WORLD man-o-war 351 block stroke that to a 408 with 14:8 compression(http://www.themustangdepot.com/servlet/StoreFront?sfs=b328f1b7a), AFR 225 heads with 58cc, comp cams big mutha thumpa camshaft and hydraulic lifters, with edelbrock performer manifold withe performer series 750 carb,jegs noisier gear drive, and some other things. first of all how much horse power do you guys think it will put out, and will i always have to run 116 octane gas, because im not carying those vp racing tanks in my trunk every where i go.