I just ordered my heads today, got World S/R Torquers 67cc chamber. I also ordered set of Comp Magnum roller rockers to go along with my Comp 280 cam and Edelbrock Torquer 2 intake. How much power do u think this combo will make on a 0.30 over 350 with flattop pistons? Going to be running a 700 Holley. Also how long does it useally take for a head and cam swap? I have all of the parts and pieces, just need the time to put it together.